Table of Contents
Introduction
Market Overview
Technology
The Consensus Mechanism
- Multi-Level BFT
- The Block Settlement Process
- The Block Finalization Process
- Reward and Penalty for Validators and Guardians
Turing-Complete Smart Contract Support
Off-Chain Micropayment Support
Ledger Storage System
Team
- Leadership
- Blockchain Team
- Media Advisors
- Blockchain Advisors
Partnerships
- SLIVER.tv and Theta Investors
Network Statistics
Use case
Social metrics
Markets and volume
TA
Competitors
Roadmap
Token Mechanics
Token Metrics
Summary
Introduction
The Theta Network is a blockchain and token as the incentive mechanism for a decentralized video streaming and delivery network. Using the Ethereum EVM “World Computer” metaphor, the Theta Network can be viewed as the “World Cache” formed by the memory and bandwidth resources contributed by viewers. The Theta Network protocol solves various challenges the video streaming industry faces today. First, tokens on the Theta blockchain are used as an incentive to encourage individual users to share their redundant computing and bandwidth resources as caching or relay nodes for video streams. This improves the quality of stream delivery and solves the “last-mile” delivery problem, the main bottleneck for traditional content delivery pipelines, especially for high resolution high bitrate 4k, 8k and next generation streams. Second, with sufficient network density the majority of viewers will pull streams from peering caching nodes, allowing video platforms to significantly reduce content delivery network (CDN) costs. More importantly, by introducing tokens as an end-user incentive mechanism the Theta Network allows video platforms to deepen viewer engagement, drive incremental revenues, and differentiate their content and viewing experience from their competitors.
The Theta blockchain introduces three main novel concepts:
● Multi-Level BFT: A modified BFT consensus mechanism which allows thousands of nodes to participate in the consensus process, while still supporting very high transaction throughput (1,000+ TPS).
● Aggregated Signature Gossip Scheme which significantly reduces messaging complexity.
● Resource Oriented Micropayment Pool: An off-chain “Resource Oriented Micropayment Pool” that is purpose-built for video streaming. It allows a user to create an off-chain micropayment pool that any other user can withdraw from using off-chain transactions, and is double-spend resistant. It is much more flexible compared to off-chain payment channels.
Market Overview
Video Streaming (SVoD) worldwide:
- Revenue in the Video Streaming (SVoD) segment amounts to US$24771 million in 2019.
- Revenue is expected to show an annual growth rate (CAGR 2019–2023) of 3.2%, resulting in a market volume of US$28151 million by 2023.
- User penetration is 14.5% in 2019 and is expected to hit 16.2% by 2023.
- The average revenue per user (ARPU) currently amounts to US$23.22.
- In global comparison, most revenue is generated in the United States (US$11420 million in 2019).
Technology
The Consensus Mechanism
Multi-Level BFT
The Theta Ledger is built on a novel multi-level BFT consensus mechanism which allows thousands of nodes to participate in the consensus process, while still supporting very high transaction throughput (1000+ TPS).
The core idea is to have a small set of nodes, which forms the validator committee, produce a chain of blocks as fast as possible using a PBFT-like process. With a sufficient number of validators (e.g. 10 to 20), the validator committee can produce blocks at a fast speed, and still retain a high degree of difficulty to prevent an adversary from compromising the integrity of the blockchain. Hence, it is reasonable to expect that there is a very high probability the validators will produce a chain of blocks without forks. Then, the thousands of consensus participants, called guardians, can finalize the chain generated by the validator committee. Here “finalization” means to convince each honest guardian that more than 2/3 of all the other guardians see the same chain of blocks.
Since there are many more guardians than validators, it could a take longer time for the guardians to reach consensus than the validator committee. In order for the guardians to finalize the chain of blocks at the same speed that the validator committee produces new blocks, the guardian nodes can process the blocks at a much coarser grain. To be more specific, they only need to agree on the hash of the checkpoint blocks, i.e. blocks whose height are a multiple of some integer T (e.g. T = 100). This “leapfrogging” finalization strategy leverages the immutability characteristic of the blockchain data structure — as long as two guardian nodes agree on the hash of a block, with overwhelming probability, they will have exactly the same copy of the entire blockchain up to that block. Finalizing only the checkpoint blocks gives sufficient time for the thousands of guardians to reach consensus. Hence, with this strategy, the two independent processes, i.e., block production and finalization, can advance at the same pace.
Under the normal condition, finalizing a checkpoint block is similar to the “commit” step of the celebrated PBFT algorithm since each guardian has already stored the checkpoint block locally. Moreover, the checkpoint block has been signed by the validator committee, and hence it is highly likely that all the honest guardians have the same checkpoint. Thus, it is only a need of protocol for the honest guardians to confirm that indeed more than 2/3 of all guardians have the same checkpoint hash.
To implement this protocol, a naive all-to-all broadcasting of the checkpoint block hash could work, but it yields quadratic communication overhead, and so cannot scale to large numbers of guardians. Instead the team proposes an aggregated signature gossip scheme which could significantly reduce messaging complexity. The core idea is rather simple. Each guardian node keeps combining the partially aggregated signatures from all its neighbors, and then gossips out the aggregated signature, along with a compact bitmap which encodes the list of signers. This way the signature share of each node can reach other nodes at exponential speed utilizing the gossip protocol. Within O(log n) iterations, with high probability, all the honest guardian nodes should have a string which aggregates the signatures from all other honest nodes if there is no network partition. In addition, the signature aggregation keeps the size of the node-to-node messages small, and thus further reduces the communication overhead.
As mentioned above, the validator committee is comprised of a limited set of validator nodes, typically in the range of ten to twenty. They can be selected through an election process, or a randomized process, and may be subject to rotation to improve security. To be eligible to join the validator committee, a node needs to lock up a certain amount of stake for a period of time, which can be slashed if malicious behavior is detected. The blocks that the committee reaches consensus on are called settled blocks, and the process to settle the blocks is called the block settlement process.
The guardian pool is a superset of the validator committee, i.e. a validator is also a guardian. The pool contains a large number of nodes, which could be in the range of thousands. With a certain amount of tokens locked up for a period of time, any node in the network can instantly become a guardian. The guardians download and examine the chain of blocks generated by the validator committee and try to reach consensus on the the checkpoints with the above described “leapfrogging” approach. The blocks that the guardian pool has reached consensus on are called finalized blocks, and the process to finalize the blocks is called the block finalization process.
The name multi-level BFT consensus mechanism reflects the fact that the validator/guardian division provides multiple levels of security guarantee. The validator committee provides the first level of protection — with 10 to 20 validators, the committee can come to consensus quickly. Yet it is resistant enough to attacks — in fact, it already provides a similar level of security compared to the DPoS mechanism if each validator nodes is run by an independent entity. Thus, a transaction can already be considered safe when it has been included in a settled block, especially for low stake transactions. The guardian pool forms the second line of defense. With thousands of nodes, it is substantially more difficult for attackers to compromise blockchain integrity, and thus provides a much higher level of security. In the unlikely event that the validator committee is fully controlled by attackers, the guardians can re-elect the validators, and the blockchain can restart, advancing from the most recent block finalized by the guardians. A transaction is considered irreversible when it is included in a finalized block. The team believes this mechanism achieves a good balance among transaction throughput, consistency, and level of decentralization, the three corners of the so-called “impossible triangle”.
The multi-level security scheme suits video streaming applications well. For streaming platforms, most of the transactions are micropayments which typically have low value, but require fast confirmation. For such low stake payments, the users only need to wait for block settlement, which is very fast, in a matter of seconds. For high stake transfers, the user can wait longer until the block containing the transaction is finalized, which could take slightly longer time, but is still in the range of minutes.
The Block Settlement Process
Inspired by recent Proof-of-Stake research works including Tendermint, Casper FFG, and Hot-Stuff, the team has designed and implemented the block settlement algorithm described below. It employs a rotating block proposer strategy where the validators take turns to propose new blocks. Then, the committee votes on the blocks to determine their order using a protocol similar to Casper FFG and Hot-Stuff.
Block Proposal
The validators rotate in a round robin fashion to play the role of block proposer, which is responsible for proposing the next block for the validator committee to vote on. To enable the round robin rotation, each proposer maintains a local logical clock called epoch. Assuming there are m validators, during epoch t, the validator with index (t mod m) is elected as the proposer for that epoch.
1) The epoch t should not be stalled so the liveness of the proposer rotation is guaranteed; and
2) The epoch t of different validators should be mostly in sync, i.e. most of the time all the validators have the same t value, so they can agree on which node should produce the next block.
Below is the protocol for proposer election and block proposal.
The protocol defines a message EpochChange(t + 1), which can be viewed as a synchronization message passed among the validators to assist them to advance to the next epoch t + 1 together. Essentially, a validator broadcasts message EpochChange(t + 1) to all other validators if any of the following conditions is met:
1) the node has proposed or voted for a block in epoch t, or
2) the node has received m/3 + 1 EpochChange(t + 1) messages from other validators, or
3) the node timed out for epoch t (the timeout is set to 4 Δ).
On the other hand, the validator enters epoch t + 1 when it has received 2m/3 EpochChange(t+1) messages from other nodes.
This protocol meets the above two requirements.
Eventual Progression: All the honest nodes will eventually enter epoch t + 1. In the worst case, all the honest nodes (at least 2m/3 + 1 nodes) reach timeout and broadcast the EpochChange(t+1) messages. Under the timing model assumption, all these messages will be delivered within time Δ after being sent out. Thus each honest node will receive at least 2m/3 EpochChange(t + 1) messages, and it then enters epoch t + 1.
Epoch Synchrony: Intuitively, this means the epochs of all the honest nodes “move together”. More precisely, the time any two honest nodes enter epoch t + 1 differ by at most most 2 Δ. To prove this, it is noted that since there are at most f faulty nodes, for the first honest node to enter epoch t + 1, at least m/3 other honest nodes must have broadcasted the EpochChange(t + 1) messages. This honest node then also broadcasts an EpochChange(t + 1) message following the protocol. After at most Δ, any honest node should have received at least m/3 + 1 EpochChange(t + 1) messages, which triggers them to also broadcast the EpochChange(t + 1) message. After Δ, all the honest nodes receive 2m/3 EpochChange(t + 1) messages and enter epoch t + 1. Thus, at most 2 Δ after the first honest node enters epoch t +1, the last honest node will enters the same epoch.
In practice, when the network latency is small enough, all the honest nodes should enter epoch t + 1 at almost the same time. As a result, they can agree on who is the next proposer. Also, for the actual implementation, the EpochChange(t + 1) messages can be combined with other types of messages (e.g. block votes) to improve the efficiency. So that in the normal case, no additional synchronization overhead is added to the system for epoch changes.
Block Consensus Among Validators
In the Theta Ledger blockchain, the header of each block contains a hash pointer to its parent block. Two blocks are conflicting if neither block is an ancestor of the other. If there are multiple, conflicting block proposals for the same epoch, an honest validator keeps all of them until one becomes settled, and then it discards all conflicting blocks.
The block settlement protocol operates epoch by epoch. The proposer for the current epoch sends to all validators a block proposal. A validator reacts by broadcasting a vote for the block. All messages are signed by their senders.
The header of the proposed block might carry a commit-certificate, which consists of at least (2m/3 + 1) signed votes for its parent block. Under the assumption that no more than m/3 validators are faulty, at most one block per height can obtain a commit-certificate. A commit-certificate for a block indicates this block and all its predecessors are committed. The proposed block may carry no commit-certificate, if its parent block did not get ≥ 2m/3 + 1 signed votes.
For the validators that are not the current proposer, their job is to vote on the proposed blocks. Once a validator receives the new block, it broadcasts a signed vote to all validators, so it can be collected by the proposer of the next epoch to form the commit-certificate. If two consecutive blocks A and B both receive a commit-certificate, then the parent block A and all its predecessors are considered settled. To ensure safety, it is required that honest nodes never vote for a block that conflicts with a settled block. When there are forks, the honest nodes should vote for the blocks on the longest fork. The figure below illustrates the block settlement process. Assume that the proposer for height 101 is faulty, and it proposed two conflicting blocks X101 and Y101, which leads to two branches. Assuming neither block X101 nor Y101 gets ≥ 2m/3 + 1 votes, then, neither the header of X102 nor Y102 contains the commit-certificate. However, at some point branch X grows faster, and two consecutive blocks X102 and X103 both obtain ≥ 2m/3 + 1 votes. After that the upper branch X up to block X102 is considered settled. And the lower branch Y can be discarded.
The above example also illustrates one advantage of the implementation compared to other PBFT based protocols like Tendermint — a block that does not receive a commit-certificate can also be included in the settled chain, as long as one of its successor blocks is settled. For instance, block X101 in the example did not get a commit-certificate, but after block X102 is settled, it is also considered settled. This reduces the waste of computation power and helps increase the transaction throughput.
The Block Finalization Process
The “leapfrogging” block finalization process in detail. As mentioned above, the guardians only need to reach consensus on the hashes of the checkpoint blocks, which are the blocks whose heights are multiple of some integer T (e.g. T = 100).
To see why it is sufficient to finalize just the checkpoint blocks, the team notes that the transaction execution engine of the blockchain software can be viewed as a “deterministic state machine”, whereas a transaction can be viewed as a deterministic state transfer function. If two nodes run the same state machine, then from an identical initial state, after executing the same sequence of transactions, they will reach an identical end state. Note that this is true even when some of the transactions are invalid, as long as those transactions can be detected by the state machine and skipped. For example, assume there is a transaction that tries to spend more tokens than the balance of the source account. The state machine can simply skip this transaction after performing a sanity check. This way the “bad” transactions have no impact on the state.
In the context of blockchain, if all the honest nodes have the same copy of the blockchain, they can be ensured to arrive at the same end state after processing all the blocks in order. But with one caveat — the blockchain might contain a huge amount of data. How can two honest nodes compare whether they have the same chain of blocks efficiently?
Here the immutability characteristic of the blockchain data structure becomes highly relevant. Since the header of each block contains the hash of the previous block, as long as two nodes have the same hash of the checkpoint block, with overwhelming probability, they should have an identical chain of blocks from genesis up to the checkpoint. Of course each guardian node needs to verify the integrity of the blockchain. In particular, the block hash embedded in each block header is actually the hash of the previous block. The team notes that a node can perform the integrity checks on its own, no communication with other nodes is required.
Interestingly, the immutability characteristic also enhances the tolerance to network asynchrony or even partition. With network partition, the guardians may not be able to reach consensus on the hash of a checkpoint. However, after the network is recovered, they can move on to vote on the next checkpoint. If they can then reach agreement, then all the blocks up to the next checkpoint are finalized, regardless of whether or not they have consensus on the current checkpoint.
To provide byzantine fault tolerance, an honest node needs to be assured that at least two-thirds of the guardians have the same checkpoint block hash. Hence it needs to receive signatures for a checkpoint hash from at least two-third of all guardians before the node can mark the checkpoint as finalized. This is to ensure safety, which is similar to the “commit” step in the celebrated PBFT protocol.
Since the guardians only need to vote on checkpoint hashes every T blocks, they have more time to reach consensus. A straightforward implementation of checkpoint finalization is thus to follow the PBFT “commit” step where each guardian broadcasts its signature to all other guardians. This requires each node to send, receive and process O(n) messages, where each message can be a couple kilobytes long. Even with T blocks time, this approach still cannot scale beyond a couple hundred guardian nodes, unless a large T value is selected, which is undesirable since it increases the block finalization latency.
Scaling to Thousands of Guardians
To reduce the communication complexity and scale to thousands of guardians, the team has designed an aggregated signature gossip scheme inspired by the BLS signature aggregation technique and the gossip protocol. The scheme requires each guardian node to process a much smaller number of messages to reach consensus, which is much more practical. Below are the steps of the aggregated signature gossip protocol. It uses the BLS algorithm for signature aggregation.
The core idea is rather simple. Each guardian node keeps combining the partially aggregated signatures from its neighbors, and then gossips this newly aggregated signature out. This way the signature share of each node can reach other nodes at exponential speed by using the gossip protocol. In addition, the signature aggregation keeps the size of the messages small, and thus reduces the communication overhead.
In the above diagram, i is the index of the current guardian node. The first line of the protocol uses function SignBLS() to generate its initial aggregated signature σi. It essentially signs a message which is the concatenation of the height and hash of the checkpoint block using the BLS signature algorithm, with multiplicative cyclic group G of prime order p, and generator g:
In the first formula above, function H : G × {0, 1}* → G is a hash function that takes both the public key pki and the message as input. This is to prevent the rogue public-key attack .
The protocol also uses function InitSignerVector() to initialize the signer vector ci, which is an n dimensional integer vector whose jth entry represents how many times the jth guardian has signed the aggregated signature. After initialization, its ith entry is set to 1, and the remaining entries are all set to 0.
After initialization, the guardian enters a loop. In each iteration, the guardian first sends out its current aggregated signature σi and the signer vector ci to all its neighbors. Then, if it has not i ci considered the checkpoint as finalized, it waits for the signature and signer vector from all its neighbors, or waits until timeout. Upon receiving all the signature and signer vectors, it checks the validity of ( σj, cj) using the BLS aggregated signature verification algorithm.
where e : G × G → Gt a bilinear mapping function from G × G to GT, another multiplicative cyclic group also of prime order p. All the invalid signatures and their associated signer vectors are discarded for the next aggregation step. It is worth pointing out that besides height cp , hashcp , the above check also requires the public key pku of the relevant guardians as input. All this information should be available locally, since when a guardian locks up its stake, its public key should be attached to the stake locking transaction which has already been written into the blockchain. Hence, no communication with other nodes is necessary to retrieve these inputs.
The aggregation step aggregates the BLS signature σj, and updates the signer vector cj . Note that for the vector update, the team takes mod p for each entry. This guarantees that the entries of vector cj can always be represented with a limited number of bits.
The algorithm then calculates the number of unique signers of the aggregated signature.
Here function I: {true, false} → {1, 0} maps a true condition to 1, and false to 0. Hence the summation counts how many unique signers have contributed to the aggregated signature. If the signature is signed by more than two-third of all the guardians, the guardian considers the checkpoint to be finalized.
If the checkpoint is finalized, the aggregated signature will be gossipped out in the next iteration. Hence within O(log(n)) iterations all the honest guardians will have an aggregated signature that is signed by more than two-third of all the guardians if the network is not partitioned.
The loop has L iterations, L should be in the order of O(log(n)) to allow the signature to propagate through the network.
Reward and Penalty for Validators and Guardians
The token reward and penalty structure is essential to encourage nodes to participate in the consensus process, and not to deviate from the protocol.
Both the validators and guardians can obtain a token reward. Each block includes a special Coinbase transaction that deposits newly minted tokens to the validator and guardian addresses. All the validators can get a share of tokens for each block. For guardians, rewarding every guardian for each block might not be practical since their number is large. Instead, the team proposes the following algorithm to randomly pick a limited number of guardians as the reward recipient for each block.
Denote the height of the newly proposed block by l, and cp is the most recently finalized checkpoint. The proposer should have received the aggregated signature σcp and corresponding signer vector ccp for checkpoint cp. Upon validating (σcp, ccp) , the proposer can check the following condition for each guardian whose corresponding entry in vector ccp is not zero (i.e. that guardian signed the checkpoint)
where Bl−1 is the hash of the block with height l − 1 , and is the sameH : G × {0, 1}* → G hash function used in the BLS signature algorithm. If the inequality holds, the proposer adds the guardian with public key pki to the Coinbase transaction recipient list. Threshold τ is chosen properly such that only a small number of guardians are included. The proposer should also attach (σcp, ccp) to the Coinbase transaction as the proof for the reward.
The Theta ledger also enforces a token penalty should any malicious behavior be detected. In particular, if a block proposer signs conflicting blocks for the same height, or if a validator votes for different blocks of the same height, they should be penalized. To become either a validator or a guardian, a node needs to lock up a certain amount of tokens for a period of time. The penalty will be deducted from their locked tokens. The node that detects the malicious behavior can submit a special Slash transaction to the blockchain. The proof of the malicious behavior (e.g. signatures for conflicting blocks) should be attached to the Slash transaction. The penalty tokens will be pulled from the malicious node and awarded to the node that submitted the first Slash transaction.
In the unlikely event that more than one-third of the validators are compromised, the malicious validators can attempt to perform the double spending attack by forking the blockchain from a block that is settled but not yet finalized. However, this is detectable by the guardian pool, since forking will generate multiple blocks with the same height, but signed by more than two-third of the validators. In this case, the validators that conducted the double signing will be penalized, and the entire validator committee will be re-elected. After the validator committee is reinstated, the blockchain can continue to advance from the most recent finalized checkpoint.
Turing-Complete Smart Contract Support
This Theta Ledger offers a smart contract runtime environment fully compatible with the Ethereum Virtual Machine. It provides full-fledged support for Turing-Complete smart contracts. Solidity-based Ethereum smart contracts can be ported to the Theta Ledger with little effort. Solidity has grown a large developer community and the prospect of allowing that proven talent pool to also contribute to Theta without reinventing the wheel was a prime consideration in enabling compatibility with the Ethereum Virtual Machine.
Off-Chain Micropayment Support
Support for high transaction throughput is a must for a video streaming focused blockchain. The team builds the support for off-chain payment directly into the ledger to facilitate high volumes of transactions.
Resource Oriented Micropayment Pool
The team has designed and implemented an off-chain “Resource Oriented Micropayment Pool” that is purpose-built for video streaming. It allows a user to create an off-chain micropayment pool that any other user can withdraw from using off-chain transactions, and is double-spend resistant. It is much more flexible compared to off-chain payment channels. In particular, for the video streaming use case, it allows a viewer to pay for video content pulled from multiple caching nodes without on-chain transactions. By replacing on-chain transactions with off-chain payments, the built-in “Resource Oriented Micropayment Pool” significantly improves the scalability of the blockchain.
The following scenario and diagram provide a comprehensive walkthrough of how the Resource Oriented Micropayment Pool works in application.
Step 1. Micropayment pool creation: As the first step, Alice publishes an on-chain transaction to create a micropayment pool with a time-lock and a slashable collateral.
CreatePool(resourceId, deposit, collateral, duration)
A couple things to be noted. To create the pool, Alice needs to specify the “Resource ID” resourceId that uniquely represents the digital content she intends to retrieve. It may refer to a video file, or a live stream.
The deposit amount needs to be at least the total value of the resource to be retrieved. For instance, if the resource is a video file which is worth 10 tokens, then the deposit has to be at least 10 tokens.
The collateral is required to discourage Alice from double spending. If a double spending attempt from Alice is detected by the validators of the blockchain, the collateral will be slashed.
The duration is a time-lock similar to that of a standard payment channel. Any withdrawal from the payment pool has to be before the time-lock expires.
The blockchain returns Alice the Merkle proof of the CreatePool transaction after it has been committed to the blockchain, as well as createPoolTxHash, the transaction hash of the CreatePool transaction.
● Step 2. Initial handshake between peers: Whenever Alice wants to retrieve the specified resource from a peer (Bob, Carol, or David, etc.). She sends the Merkle proof of the on-chain CreatePool transaction to that peer. The recipient peer verifies the Merkle proof to ensure that the pool has sufficient deposit and collateral for the requested resource, and both parties can proceed to the next steps.
● Step 3. Off-chain micropayments: Alice signs ServicePayment transactions and sends them to the peers off-chain in exchange for parts of the specified resource (e.g. a piece of the video file, a live stream segment, etc.). The ServicePayment transaction contains the following data:
targetAddress, transferAmount, createPoolTxHash, targetSettlementSequence,
Sign(SKA, targetAddress || transferAmount || createPoolTxHash ||
targetSettlementSequence)
The targetAddress is the address of the peer that Alice retrieves the resource from, and the transferAmount is the amount of token payment Alice intends to send. The targetSettlementSequence is to prevent a replay attack. It is similar to the “nonce” parameter in an Ethereum transaction. If a target publishes a ServicePayment transaction to the blockchain, its targetSettlementSequence needs to increment by one.
The recipient peer needs to verify the off-chain transactions and the signatures. Upon validation, the peer can send Alice the resource specified by the CreatePool transaction.
Also, the off-chain ServicePayment transactions are sent directly between two peers. Hence there is no scalability bottleneck for this step.
● Step 4. On-chain settlement: Any peer that received the ServicePayment transactions from Alice can publish the signed transactions to the blockchain anytime before the timelock expires to withdraw the tokens. It is called the ServicePayment transactions that are published the “on-chain settlement” transactions.
Note that the recipient peers needs to pay for the gas fee for the on-chain settlement transaction. To pay less transaction fees, they would have the incentive to publish on-chain settlements only when necessary, which is beneficial to the scalability of the network.
No on-chain transaction is needed when Alice switches from one peer to another to retrieve the resource. In the video streaming context, this means the viewer can switch to any caching node at any time without making an on-chain transaction that could potentially block or delay the video stream delivery. As shown in the figure, in the event that Bob leaves, Alice can switch to Carol after receiving k chunks from Bob, and keep receiving video segments without an on-chain transaction.
Moreover, the total amount of tokens needed to create the micropayment pool is (collateral + deposit), which can be as low as twice of the value of the requested resource, no matter how many peers Alice retrieves the resource from. Using computational complexity language, the amount of reserved token reduces from O(n) to O(1) compared to the unidirectional payment channel approach, where n is the number of peers Alice retrieves the resource from.
Double Spending Detection and Penalty Analysis
To prevent Alice, the creator of the micropayment pool from double spending, we need to 1) be able to detect double spending, and 2) ensure that the net value Alice gains from double spending is strictly negative.
Detecting double spending is relatively straightforward. The validators of the Theta Network check every on-chain transaction. If a remaining deposit in the micropayment pool cannot cover the next consolidated payment transaction signed by both Alice and another peer, the validators will consider that Alice has conducted a double spend.
Next, we need to make Alice worse off if she double spends. This is where the collateral comes in. The amount of collateral tokens has to be larger than the deposit. And here is why.
In the Figure below, Bob, Carol, and David are honest. Alice is malicious. Even worse, she colludes with another malicious peer Edward. Alice exchanges partially signed transactions with Bob, Carol, and David for the specified resource. Since Alice gains no extra value for the duplicated resource, the maximum value she gets from Bob, Carol, and David is at most the deposit amount. As Alice colludes with Edward, she can send Edward the full deposit amount. She then asks Edward to commit the settlement transaction before anyone else and return her the deposit later. In other words, Alice gets the resource which is worth at most the deposit amount for free, before the double spending is detected. Later when Bob, Carol, or David commit the settlement transaction, the double spending is detected, and the full collateral amount will be slashed. Hence, the net return for Alice is
netAlice = deposit collateral
Therefore, we can conclude that for this scenario, as long as collateral > deposit, Alice’s net return is negative. Hence, if Alice is rational, she would not have any incentive to double spend.
We can conduct similar analysis for other cases. The details are omitted here, but it can be shown that in all cases Alice’s net return is always negative if she conducts a double spend.
Another case is that Alice is honest, but some of her peers are malicious. After Alice sends micropayment to one of those peers, it might not return Alice the resource she wants. In this case, Alice can turn to another peer to get the resource. Since each incremental micropayment can be infinitesimally small in theory, Alice’s loss can be made arbitrarily small.
Ledger Storage System
Storage Microservice Architecture
To harness the processing and storage power of server clusters, the key design decision is to adopt the popular microservice architecture commonly seen for modern web service backends, where different modules of the ledger can be configured to run on different machines. In particular, the consensus module and the storage module can be separated. Potentially the consensus module can run on multiple machines using the MapReduce framework to process transactions in parallel.
The Theta Ledger stores both the transaction blocks and the account state history, similar to Ethereum. The bottom layer of the storage module is a key value store. The Theta Ledger implements the interfaces for multiple databases, ranging from single machine LevelDB to cloud based NoSQL database such as MongoDB, which can store virtually unlimited amount of data. Thus the ledger can run on one single computer, and can also be configured to run on server clusters.
History Pruning
While the microservice architecture suits the powerful server clusters well, it is still a storage space constraints when running the ledger on a lower-end home PC. The team has designed several techniques to reduce the storage consumption.
Similar to Ethereum, the Theta Ledger stores the entire state for each block, and the state tree root is saved in the header of the corresponding block. To reduce the space consumed by the state history, the Theta Ledger implements state history pruning, which leverages a technique called reference counting illustrated in the figure below.
The ledger state is stored using a Merkle-Patricia tree. Figure (a) depicts the initial state tree, whose root is denoted by State 0. Each node in the tree has an attribute called the “reference count”, which is equal to the number of parents of the node. In the initial state tree, each node has only one parent, so the reference count are all set to 1.
In Figure (b), account A is updated to A* after applying the transactions in the newly settled block. Hence a new Merkle state root State 1 is created, along with the Merkle branch connecting the new root State 1 and A* (the blue nodes and edges). Since new nodes are added, the reference count of direct children of these new nodes is updated from 1 to 2.
At some point the team decided to delete State 0 to save some storage space. This is done by deleting the nodes whose reference count is zero recursively starting from the root State 0, until no node can be deleted. Whenever a node is deleted, the reference count of all its children will be decremented by one. Figure © illustrates the process, and Figure (d) shows the result of the pruning. To achieve the maximum level to state storage compaction, once a block is finalized by the guardian pool, all the history prior to that block can be deleted. The ledger can also be configured to keep a limited history of states, for example, the state trees of the latest 1000 blocks, depending on the available storage space.
It can be shown that with the reference counting technique, pruning a state tree has the time complexity of O(k log N), where k is the number of accounts updated by the transactions in one block, and N is the total number of accounts. Typically, k is in the range of a couple hundreds to a thousand. Hence, pruning a state tree should be pretty efficient and should not take much time.
Managing the space consumed by the transaction blocks is even simpler, after a block is finalized, all its previous blocks can simply be deleted, or can be kept a limited history similar to the state trees.
With these techniques, common PCs and laptops are sufficient to run the guardian nodes.
State Synchronization
One of the pain points using earlier generation blockchains is the state synchronization time. After spinning up a new node, typically it needs to download the full block history all the way from the genesis block. This could take days to complete, and already becomes a hurdle for user adoption.
The state and block history stored by the full nodes can help reduce the synchronization time dramatically. After a new node start, the first step is to download all the validator and guardian join/leave transactions and the headers of the blocks that contain these special transaction up to the latest finalized block. With these special transactions and the headers which contain the validator and guardian signatures, the new node can derive the current validator committee and guardian pool. Since the validator and guardian set changes are relatively infrequent, the amount of data need to be downloaded and verified for this step should be minimal.
In the second step, the new node downloads the state tree corresponding to the latest finalized block. And it needs to confirm that the root hash of the tree equals the state hash stored in the latest finalized block. Finally, the new node verifies the integrity of the state tree. If all the checks are passed, the new node can start listening to new blocks and start participating in the consensus process.
Team
According to the Theta website, there are about 20 members in the team. The team mainly consists of tech specialists of different level, who used to develop streaming video applications and participated in projects related to virtual reality. Some of them have received patents on technologies that are used in the media field. Most of the team members worked for SLIVER.tv.
The team is led by Mitch Liu, previously the co-founder of SLIVER.tv, Gameview Studios, and Tapjoy, he also holds an MBA from Stanford Graduate School of Business. The second co-founder is Jieyi Long, who was also a co-founder at SLIVER.tv as well as holding a Ph.D. in computer engineering from Northwestern University.
Leadership
- Co-founder / CEO at Theta
- Co-founder SLIVER.tv
- Co-founder Gameview Studios
- Co-founder Tapjoy
- BS in Computer Science & Engineering from MIT
- MBA from Stanford Graduate School of Business
Mitch Liu is the co-founder and CEO of SLIVER.tv, the leading esports entertainment platform with patented technology to live stream top esports events in fully immersive 360° VR in partnership with Intel Extreme Masters, Turner ELEAGUE, ESL One and Dreamhack among other global tournament operators. Along with his co-founder Mr. Long, they currently hold two patents and two additional pending patents for virtual reality 360° video streaming, and new algorithms for generating highly efficient live spherical video streams.
In 2010, Mr. Liu co-founded Gameview Studios best known for its Tap Fish mobile game franchise with nearly 100 Million downloads. The company was acquired by DeNA, a leading Japanese mobile gaming company within 6 months of launch. Prior to that, he co-founded Tapjoy in 2007, a pioneer of rewarded social and mobile video advertising, and grew that company to $100MM in revenues.
- Co-founder / CTO at Theta
- Co-founder SLIVER.tv
- BS in Microelectronics, Peking University
- PhD in Computer Engineering, Northwestern University
- Developed multiple patented technologies including VR live streaming as well as instant replays for video games.
Jieyi Long is the co-founder and Chief Technology Officer of SLIVER.tv. He leads the technical team and developed multiple patented technologies including VR live streaming and instant replay for video games. He received a B.S. degree in Microelectronics from Peking University in Beijing, China. He also received a Ph.D. degree in Computer Engineering from Northwestern University in Evanston, IL where he conducted research in mathematical modeling and algorithms to optimize large scale electronics systems, and a cryptography enthusiast.
- Chief Product Officer at Theta
- Chief Product Officer at SLIVER.tv
- Designed and launched virtual currency systems for a variety of platforms.
- Director at Tencent for the Wechat app
- Cofounder of a live video streaming app for foodies
Ryan Nichols is the Head of Product and Platform for SLIVER.tv. He leads the company’s eSports entertainment platform built around one of the largest esports virtual economies with 1B+ virtual tokens circulated within two months of launch. Leading previous startups, he’s designed and launched virtual currency systems for a variety of multiplayer games, including a cross-game virtual currency API used by hundreds of third-party game developers and tens of millions of players worldwide. Mr. Nichols was a director for Tencent on the globally popular WeChat app, and a co-founder of a live video streaming app for foodies.
Blockchain Team
Jieyi Long — Co-founder / CTO
Ribao Wei — Principal Engineer
Education:
- Beijing University of Posts and Telecommunications. Degree Name — Bachelor’s degree. Field Of Study — Information Security.
- George Mason University.
Experience:
- Nutanix — Member of Technical Staff. Dates Employed: Apr 2015 — Jan 2018.
- Visa — Senior Software Engineer. Dates Employed: Jul 2014 — Apr 2015.
- Model N — Member of Technical Staff. Dates Employed: Dec 2012 — Jul 2014.
Roy Zheng — Streaming Architect
Education:
- University of Maryland. Degree Name — Master’s Degree. Field Of Study — Computer vision, machine learning.
- Xidian University. Degree Name — Bachelor’s Degree. Field Of Study — Communication and Signal Processing.
Experience:
- SLIVER.tv — Streaming achitect & developer. Dates Employed: Apr 2016 — Present
- Akamai Technologies — Senior System Engineer. Dates Employed: Sep 2011 — Feb 2015. Backend media server design. Distributed computing. Media streaming, storage and content delivery.
- Cisco Systems — Senior System Engineer. Dates Employed: May 2006 — Sep 2011.
- Applied Data Systems — Senior Software Engineer. Dates Employed: Sep 2005 — Jun 2006.
- Lucent Technologies. Senior Software Engineer. Dates Employed: Feb 2005 — Sep 2005.
Qinwei Gong — Platform Architect
Education:
- University of Wisconsin-Madison. Degree Name — MS. Field Of Study — Computer Science.
Shanghai University of International Business and Economics.
Experience:
- SLIVER.tv — Software Architect. Dates Employed: May 2017 — Present.
- AppMarq — Creator. Dates Employed: Feb 2016 — Present. AppMarq is an iOS app with which you can bookmark all your favorite pages from different iOS apps into one place.
- Branch Metrics — Senior Software Engineer. Dates Employed: Oct 2014 — Mar 2016.
- Bill.com — Senior Software Engineer. Dates Employed: May 2012 — Sep 2014.
- Magnet Systems Inc. — Sr. Software Engineer. Dates Employed: Feb 2011 — Apr 2012.
- Yahoo! — Techinical Yahoo! Dates Employed: Sep 2005 — Jun 2010.
- YesVideo — Software Engineer. Dates Employed: 2004–2005.
Jing Xu — Blockchain Engineer
Education:
- New York University
- Peking University
Experience:
- SLIVER.tv & Theta Labs — Senior Software Engineer. Dates Employed: Mar 2018 — Present.
- IGT — Software Engineer. Dates Employed: Apr 2013 — Dec 2017.
- Chocobots Games, Inc. — Java Developer. Dates Employed: Feb 2012 — Oct 2012.
Zhenyang Tang — Blockchain Explorer Engineer
Education:
- The George Washington University. Degree Name — Master’s degree. Field Of Study — Computer Science.
- Beijing University of Technology. Degree Name — Bachelor’s degree. Field Of Study — Computer Science.
Experience:
- Aditazz Inc. Title Frontend Engineer. React, Redux, Node. Dates Employed: May 2017 — Jan 2018.
- iBeeHub Incubator — Web Developer. Dates Employed: Jul 2016 — Nov 2016.
- Hereseas Inc. — Frontend Engineer, Co-founder. Dates Employed: Jun 2015 — Jul 2016.
- Nufront — Test Engineer. Dates Employed: Jul 2013 — Sep 2013.
Rene Garcia — Platform Engineer
Education:
- University of California, Santa Cruz. Degree Name — Bachelor of Science (BS). Field Of Study — Computer Games and Programming Skills.
- Foothill College. Degree Name — Associate of Science (A.S.). Field Of Study — Computer Science.
Experience:
- SLIVER.tv — Unity Software Engineer. Dates Employed: Aug 2016 — Present. Develop VR apps for the SLIVER platform.
- Midverse Studios, Inc — Unity Developer. Dates Employed: Feb 2016 — Sep 2016
- Queix, LLC — Founder and Developer. Dates Employed: Sep 2014 — Feb 2016.
- E-centric LLC — Co-founder and Developer. Dates Employed: May 2015 — Jan 2016.
Tim Li — Head of Platform
Education:
- The University of Chicago Booth School of Business. Degree Name: Master of Business Administration. Field Of Study — Entrepreneurship; Strategy; Finance.
- University of Illinois at Urbana-Champaign. Degree Name: Bachelor’s Degree. Field Of Study — Materials Science and Engineering.
Experience:
- Andreessen Horowitz — Deal Team Intern. Dates Employed: Jun 2017 — Sep 2017.
- HERE (BMW, Daimler, Audi) — Corporate Strategy Associate. Dates Employed: Jan 2016 — May 2017. Autonomous Driving; Transportation Mobility; IoT; Smart Cities.
- Accenture Technology Labs — R&D Associate Manager. Dates Employed: Jun 2015 — Jan 2016.
- LSM — Outreach Associate. Dates Employed: Aug 2011 — Jul 2013.
- Product Innovation Research Laboratory — Technology Consultant. Dates Employed: 2010–2011.
- Texas Instruments — Operations Engineering Intern. Dates Employed: May 2010 — Aug 2010.
Wes Levitt — Head of Strategy
Education:
- University of California, Berkeley. Degree Name: Master of Business Administration. Dates attended or expected graduation: 2015–2018.
- University of Oregon. Degree Name — B.S. Field Of Study — Economics.
Experience:
- Galaxy Capital Partners — Advisor. Dates Employed: Jul 2018 — Present.
- Mosser Capital Management, LLC — Senior Investment Associates. Dates Employed: May 2016 — Feb 2018.
- Redwood Trust, Inc. — Associate. Dates Employed: Nov 2013 — Feb 2016.
- Umpqua Bank — Commercial Real Estate Portfolio Analyst. Dates Employed: Nov 2011 — Nov 2013
- Pentagon Federal Credit Union — Analyst. Dates Employed: Jun 2007 — Nov 2011.
Bruce Chong — Head of Korea Development
Education:
- The University of Texas at Austin. Degree Name — BA. Field Of Study — Economics.
- The University of Texas at Dallas — School of Management. Degree Name- Bachelor of Science. Field Of Study — Accounting and Information Management.
Experience:
- Juniper Networks — Agency Finance Manager. Dates Employed: Oct 2017 — Jan 2018.
- Core-Mark International — Senior Management Consultant. Dates Employed: Jul 2016 — Oct 2017.
- ECS Refining — Senior Financial Analyst. Dates Employed: Oct 2014 — Jul 2016.
- Robert Half Management Resources — Senior Consultant. Dates Employed: Jun 2013 — Oct 2014.
- Texas Instruments — Senior Financial Analyst. Dates Employed: 2010–2013.
- L-3 Communications — Sr. Financial Analyst. Dates Employed: Aug 2008 — Jan 2010.
Advisory Board
The advisory board includes YouTube co-founder Steve Chen, Twitch co-founder Justin Kan and others.
Media Advisors
Steve Chen — Co-founder of YouTube
Steve Chen was the co-founder and chief technology officer of YouTube. Steve was instrumental in building YouTube into a viral video phenomenon. He helped lead YouTube through the Google acquisition for $1.65 billion, less than a year after launching the site. As the key technologist, Steve developed the company’s massive data centers and helped build YouTube into a premier entertainment destination, and one of the most popular websites on the Internet today.
Clifford Morgan — CEO GFUEL
Cliff Morgan is the Founder and CEO of Gamma Labs, maker and marketer of GFUEL energy drink. Originally a Sports Nutrition company, Gamma transitioned to a direct-to-consumer e-commerce business through the early adoption of influencer marketing. GFUEL currently maintains over 200 active influencer relationships, with a combined reach of over 70 million people a month across all social media platforms. Gamma Labs has been recognized as one of the fastest growing companies in the United States for two consecutive years by the Inc. 5000.
Justin Kan — Co-founder of Twitch
Justin Kan is a serial entrepreneur and investor. He is widely known for founding Twitch, a video game streaming platform acquired for $970mm by Amazon in 2014. Justin has founded various companies including Kiko, the first AJAX web calendar; Justin.TV, a live video streaming platform; Socialcam, a mobile video sharing app; and Exec, an on-demand home cleaning service. He has additionally incubated two companies out of his home in the past 2 years: Alto , a modern online pharmacy, and Whale, a video Q&A app. Justin impacted over 900 companies as a Partner at Y Combinator from 2011–2017 and personally invested in over 65 companies, including Cruise, Zenefits, and Wave. Currently, he is the Founder and CEO of Atrium LTS, building technology to revolutionize the legal industry. Justin graduated from Yale University with a degree in Physics and Philosophy.
Kyle Okamoto — Chief Network Officer at Verizon Digital Media
Kyle Okamoto is the Chief Network Officer at Verizon Digital Media Services, overseeing the Network, Technology and Operations businesses and one of the original employees of the VDMS startup. Kyle has worked for Verizon for many years in a number of leadership roles as well as at several start-ups in the social enterprise and digital media space. He’s been instrumental in the AOL and Yahoo integration as well as the EdgeCast Networks, UpLynk and Volicon acquisitions that currently form the foundation of Verizon Digital Media Services.
Riz Virk — Executive Director at Play Labs @ MIT
Riz Virk is Executive Director at Play Labs @ MIT, as well as Chief Strategy Officer and Cofounder at BitMovio, a video entertainment marketplace. He previously cofounded and/or was an early investor in SLIVER.tv, Theta Labs, GameView Studios, and Tapjoy. Riz was the founder of Bayview Films, and independent film studio. He holds a Masters in Management from Stanford Business School and a BS in Computer Science & Engineering from MIT.
Dennis Fong — Founder Plays.tv, first esports celebrity
Dennis Fong is the Founder & CEO of Plays.tv, a video platform that helps gamers level up their play. Known as “Thresh” in gaming circles, Dennis was crowned world champion of Doom, Quake, and Quake 2, was called the “Michael Jordan of video games” by the Wall Street Journal, and inducted into the eSports Hall of Fame. Dennis is also the co-founder of several successful startups, including Xfire (acquired by Viacom), Lithium Technologies, Gamers.com and Raptr.
Rajeev Surati, PhD — MIT PhD, video compression and streaming expert
Rajeev Surati did his undergraduate through PhD at MIT and has founded and sold several companies: Flash Communications to Microsoft which formed the basis for their early IM efforts — Photo.net, the world’s largest high end amateur photography community. Based on PhD work at MIT, Rajeev cofounded Scalable Display Technologies which is a premier provider of Immersive Simulation and Entertainment creation technologies. These are life size systems and the company is profitable and based in Cambridge MA.
Sam Wick — Head of Ventures, United Talent Agency
Sam Wick is a leading digital and entertainment executive. He currently leads UTA’s new venture group. He most recently was a key member of Maker Studios’ management team where he was responsible for the enterprise P&L, corporate development, business development and strategic partnerships. He has 20+ years of experience in the media and technology space including senior positions at MySpace, AOL, Mp3.com and Sony. During this time he was involved in M&A activity including financing and acquisitions of his companies.
Karen Huh — Senior Vice President of CJ Hello
Karen is Senior Vice President of CJ Hello and leads their internet streaming media services business including online offerings of top Korean networks, movies, sports, animations and apps. Prior to joining CJ Hello, Karen was founder and CEO of Across, a strategy consulting and executive advisory company in the media & technology space. Before founding Across, she gained significant experience in the media space at Google. Karen began her career at LG Uplus, where she managed the online content business and launched LG’s paid Video-on-Demand service for the first time in Korea.
Blockchain Advisors
Steve Dakh — CTO at SmartWallet
Steve Dakh was an original developer on the Ethereum project, co-founder and CTO of the KryptoKit team which launched the Rushwallet, and serves as an advisor to numerous blockchain projects such as Aeternity, Po.et, and Polymath. His current project is his most sophisticated wallet project yet, SmartWallet. Steve also serves on the Faculty of Advisors of the CryptoCurrency Certification Consortium (C4).
Dovey Wan — Founding Partner of Primitive Ventures
Dovey Wan is Founding Partner of Primitive Ventures, a long-term focused cryptoasset investment fund she founded with Eric Meltzer. Prior to founding Primitive Ventures, Dovey served as Managing Director for DHVC, where she led investments in marquee blockchain projects such as Dfinity, Basic Attention Token, OmiseGo, Cosmos/Tendermint, and Kyber Network. Outside of blockchain ventures she also led investments in LimeBike, LoomAi, Chariot, Flexport, and Optimizely. She began her career at eBay, where she spent nearly 4 years progressing through Data Science Engineer, Senior Business Analyst, and Product Manager roles.
Fan Zhang — Founding member, Sequoia Capital China
Fan Zhang is a pioneer in the venture capital industry in China. He previously served as a Founding Member of Sequoia Capital China, and a Director of DFJ ePlanet Ventures’ China practice. Mr. Zhang has extensive experience investing into emerging technologies since 2001, and has been ranked multiple times by Forbes as one of leading venture capitalists in its annual China’s Midas List.
Travis Skweres — Founder CoinMkt, one of the first US bitcoin exchanges
Travis Skweres is an early entrepreneur and investor player in cryptocurrencies. Travis was the CEO and Cofounder of CoinMKT, one of the first Bitcoin exchanges based in the United States. Operating from 2013–2015, CoinMKT achieved tens of thousands of users, millions of dollars worth of Bitcoin traded, and was acquired by ANX Hong Kong in 2015. Travis remains an active investor in the cryptocurrency community and is currently working on releasing his next cryptocurrency-related project. Travis clients have included Occidental Petroleum, The Home Depot, Blinds.com, NBC Universal, and more.
Ma Haobo — CEO of aelf
Ma is the founder and CEO of aelf, a decentralized cloud computing blockchain network, as well as founder and CEO of Hoopox, a technology company that provides vertical industrial solutions from infrastructure to blockchain systems. A blockchain expert and early adopter of digital assets, Ma also previously served as CTO of GemPay and AllCoin. He is a member of Blockchain Experts’ Commission of Chinese Institute of Electronics.
Jonathan Wong — Director of Product at Rakuten Viki
Jonathan Won joined Theta Advisory Council this August. Previously, Jonathan was at Microsoft leading the Bing Ads business across Southeast Asia, India and Korea. Before that, he was the Head of Consumer Apps & Services Marketing, responsible for overall brand strategy, marketing execution and driving user adoption of Microsoft apps and services — including Internet Explorer, Outlook.com, SkyDrive and Skype — among the hundreds of millions of Internet users across Asia. Jonathan is also the founder and developer of Katsu News, a fully automated and algorithm-driven news aggregator for fans of Japanese anime, music and pop culture.
Partnerships
SLIVER.tv
The collaboration with SLIVER.tv was the first-ever integration of blockchain technology with an esports streaming video platform. SLIVER.tv is the leading esports entertainment platform and offers interactive, highly engaging streamers of top esports titles including CS:GO and PUBG. About three million users have now earned TFuel on SLIVER.tv, which they can use to donate to their favorite streamers, buy premium virtual goods and services on SLIVER.tv for their favorite games. Additionally, advertisers and brand sponsors will be able to fund ad campaigns with Theta and support key content creators. With these use cases proven by TFuel on SLIVER.tv, Theta Network plans to integrate Theta Tokens with other partner streaming sites and build adoption throughout the streaming video industry.
SamsungVR
SamsungVR is spearheading the Theta Media Advisory Council, with the goal of furthering the technical development of the Theta Network.
As part of the partnership, the Theta team works closely with the SamsungVR team as they develop the native blockchain and peer-to-peer protocol, prototyping with Samsung engineers to ensure that the network created can satisfy the streaming demands of major content providers like Samsung.
There is the Samsung x Theta channel, the second channel built on the Theta blockchain. Building the experience building the SLIVER.tv test channel, the team has successfully integrated the Theta protocol with SamsungVR, in the form of a test channel featuring 360° VR content. The channel is hosted on both SamsungVR’s website and SLIVER.tv, combining both sites’ userbases to maximize concurrent viewers and bandwidth offload efficiency. SamsungVR users can use the Theta block explorer to transparently observe how relaying video corresponds to token transactions on the Theta blockchain. This key component of token rewards is what will allow SamsungVR and other video platforms to reward users, increase their engagement, and create a robust community of viewers and video relayers.
Maekyung Broadcasting Network — MBN
The third Theta channel — MBN news network, the largest business news channel in South Korea. The channel is live broadcasting 24-hour content from MBN, powered by the Theta protocol and available to users in South Korea (or anyone browsing with a VPN pointed to South Korea).
MBN is a subsidiary of Maekyung Media Group, a diversified media company owning publishing, broadcasting and digital properties including MBN, Maeil Business Newspaper (daily economic and business newspaper), Mmoney (Business news TV channel), Maekyung.com (Business and economic news portal site/ www.mk.co.kr), Pulsenews.co.kr (Maeil Business Newspaper’s English news site) and Maekyung Economy (Weekly economic and business news magazine).
MIT Education Arcade, Play Labs
There is a strategic blockchain partnership between Theta Labs Play Labs Startup incubator which is to foster ecosystem for streaming content & blockchain during program held at MIT.
Bitmovio
BitMovio is a decentralized video platform powered by Theta and born out of Playlabs at MIT Game Lab. One of the first dapps built on Theta, it’s disrupting YouTube/Netflix by putting content back in the hands of content creators.
Pandora.tv
Pandora.tv is a major Korean video streaming platform with 15M+ monthly visits. It is a User Generated Content-based video portal and personal broadcasting service offering VOD and live video streaming globally. It also features live TV, premium on-demand movies, and major sporting events to make it a one-stop-shop for all types of video content. In addition to Korea, Pandora.tv has a major presence in Japan, where nearly half of monthly users come from.
Founded in October 2004, Pandora TV is a leading player in Korean video space. It also operates KM Player, the most-downloaded video player worldwide with 812M total downloads and 20M Monthly Active Users.
Pandora TV has raised over $16M from Silicon Valley venture capital firms including DCM Ventures and Altos Ventures. In 2007, Pandora TV won the award of Red Herring Asia 100 and Red Herring Global 100.
CJ HelloVision
CJ Hello, a cable and internet service operator, has worked with Theta on integration of mesh streaming and blockchain incentives for a variety of use cases around video streaming on various device platforms. Theta successfully deployed the Theta protocol into the CJ Viewing Box, an Android-based set top TV box. The CJ Viewing Box is a product from CJ Hello, the media and entertainment subsidiary of the $25B Korean conglomerate CJ Group. As part of this test, the Theta protocol is able to share video streams between the Viewing Box, mobile devices, and PC. Development will continue in the coming months toward deployment of this technology.
IoTeX
Additionally, Theta recently began collaborating with IoTeX, a leading project at the intersection of IoT and blockchain. The teams originally met back in July 2018, when they jointly hosted a Korea meetup with their friends at Zilliqa, Quantstamp, and Kyber Network. Now the projects are discussing the many ways they can leverage their respective blockchains and domain expertise to drive adoption of their protocols.
BRAVE
Starting July, two of the most widely-adopted blockchain projects is joining forces for an advertising partnership: SLIVER.tv / Theta became a Verified Publisher in the Brave browser, while Brave became a sponsor on SLIVER.tv, running ads along side their top streamers. Brave is an innovative privacy browser combined with a blockchain based digital advertising platform with 7 million monthly active users. The Brave browser rewards its users for opting into privacy-preserving ads by giving them 70% of the ad revenue share in Basic Attention Tokens (BAT), a utility token built on top of Ethereum. The Brave browser will also become an officially supported browser for relaying video on the Theta Network. Users can earn BAT rewards for consenting to viewing ads in the Brave browser, while at the same time earning TFUEL for relaying video on the Theta Network.
Klaytn blockchain
The Klaytn blockchain project is being developed by GroundX, the blockchain unit of Korean tech conglomerate Kakao. Klaytn is an enterprise-grade, service-centric platform that combines the best features of both public blockchains (and private blockchains via an efficient ‘hybrid’ design. GroundX has reported raised $90M in funding for the Klaytn project in a private token sale, with an additional funding round currently underway.
NASA TV
SLIVER.TV partners with NASA TV to bring exciting live events such as rocket launches, space station dockings, and spacewalks. These events are all powered by the Theta blockchain and the viewing experience is the same as those of other TFUEL channels.
Theta integration with Smart TVs
It focuses on TVs running on Android and Samsung’s Tizen operating system.Theta works on smart TVs and TV boxes to Theta runs on the latest Sony Bravia TV and the LG U+ set top box. The team is currently working on the first example of a consumer Smart TV app that can relay video content over the Theta Network, and will be revealing more about this in the near future.
SLIVER.tv and Theta Investors
DHVC
DHVC is a California-based venture capital fund that invests primarily in early stage and growth stage companies with disruptive technologies or innovative business models, big market opportunities and strong management team. Their fund focuses on innovations in high-tech space, including mobile Internet, big data, cloud computing, wearable computing, artificial intelligence, robotics, virtual reality, smart devices, gaming and entertainment, medical devices and other disruptive technologies. They invest in companies from early stage to growth stage, and they occasionally participate in later rounds of financing for extraordinary companies. They have a professional investment team with exceptional academic, industry and investment background.
Sierra Ventures
Sierra Ventures is a Bay Area based early-stage venture firm investing globally with a focus on Next Generation Enterprise and Emerging Technologies. With over three decades of experience and over $2 billion of assets under management, Sierra has created a vast network of successful entrepreneurs, Global 1000 CXOs, operational executives, and deep domain experts, providing a platform for entrepreneurs around the world Sierra Ventures primarily invests in Seed and Series A rounds, with a preference to lead investment rounds and reserve capital for follow on rounds. Sierra Ventures typically makes initial investments between $500,000 and $7 million on average and invests between $500,000 and $15 million over the life of an investment. The firm has invested in leading companies such as Intuit, Invensense, Greenplum, MakeMyTrip, OnLink, Teradata, StrataCom, Sourcefire, Treasure Data and more.
DCM Ventures
DCM Ventures is an early stage VC empowering the global ambitions of inspired entrepreneurs. DCM Ventures manages ten funds totaling $3.0 billion, and have made investments in more than 300 technology companies across the United States and Asia. With offices in the Silicon Valley, Beijing and Tokyo, DCM provides hands-on operational guidance and a vast network of global business and financial resources to its portfolio companies.
The Venture Reality Fund
The VR Fund brings expert guidance and resources to promising and early stage VR, AR and MR startups. The VR Fund seeks innovative companies across a wide variety of sectors — from infrastructure and development tools to content and applications.
Colopl Next
A venture capital that supports start-ups specialising in VR/AR, entertainment, emerging technologies, and other internet businesses. Colopl Next is the corporate venture capital of is Colopl, Inc, which is a leading Japanese gaming company. Colopl, Inc. is founded with the mission of “Entertainment in Real Life”, and constantly put its customer as first priority.
GREE
Gree is a Japanese internet media company that provides mobile social networking, and mobile technology services for its users. Gree shares development and operational expertise across all its studios as Gree always works to create new game models for its customers. In January 2011, Gree established its U.S. subsidiary and currently develops games at its studios in Japan, North America, and South Korea. Gree was ranked as Japan’s fastest-growing tech company by Deloitte Touche Tohmatsu in 2009 and 2010. It has over 190 million registered players and offers over 7,500 game applications for smartphones.
Sparkland Capital
Sparkland Capital is an early-stage venture capital firm that invests in frontier technologies. Connecting Silicon Valley and Asia, they leverage thhe deep networks to provide market intelligence, strategic advice and local relationships for founders to expand. The Sparkland team is comprised of dedicated entrepreneurs, investors, founders, and early employees from prominent technology companies. Their investment focus are VR/AR, IoT, Cyber Security, AI/Robotics, and Enterprise Software. Since 2014, they have invested in over 30 innovative startups.
Advancit Capital
Advancit Capital is an early stage investment firm focused on media, entertainment and technology companies. The firm seeks the opportunity to form long-term partnerships with talented, focused and driven entrepreneurs.
CAA Ventures
CAA Ventures is a California-based early-stage venture capital fund that offers financing solutions to consumer internet companies. CAA Ventures is the venture arm of Creative Artists Agency.
Greycroft
Greycroft is a venture capital firm that focuses on technology start-ups and investments in the Internet and mobile markets. Greycroft manages in excess of $1 billion and has made over 200 investments since inception in leading companies.
BDMI
BDMI is a venture capital firm headquartered in New York focused on innovative digital media technologies, products, and distribution channels in North America, Europe and Israel. BDMI concentrates on early stage investments in the digital media landscape. The company focuses predominantly on Series A and B investments, but also has a seed fund that includes about 20 companies. The initial investment range is from $500k to $3m. With consolidated revenues of over $25 billion, Bertelsmann is an international media company encompassing television, book and magazine publishing, music and media services in more than 60 countries.
Heuristic Capital
Heuristic Capital is an early stage hardware focused Venture Capital fund. Matched with over 25 years of professional and personal venture investment experience, they invests in and assist companies cross the hurdles of prototyping, financing, manufacturing, and business building.
Sony Innovation Fund
Sony Innovation fund is the venture capital arm of Sony Corporation and is dedicated to investing in and engaging with promising early-stage companies. Beyond investment, their mission is to provide resources such as access to the broader Sony world and its global network, as well as collaborate with startups to foster business creation in related lines of business and new areas of interest to Sony, catalyze a talented and passionate team.
gumi
gumi Inc, is a mobile entertainment content publisher and developer based in Tokyo. They have had a lot of success in Japan with both feature phone and smartphone games, their flagship smartphone title Brave Frontier was a massive hit across the globe. They also have partnerships with companies like SEGA and LINE. Source
Nirvana Capital
Nirvana Capital is a San Francisco/Beijing based blockchain fund that focused on primary market investment. Its founding partners are also early supporters of Ethereum. To bring together ecosystems that revolutionize the social productions and labor relations with the communities underneath, Nirvana Capital provides end-to-end strong support to its portfolio projects, including advisory on strategies/operations and resources matching. Their investment themes mainly include public chains and protocols.
ælf
ælf is a decentralized Cloud Computing Blockchain Network, featuring parallel processing and nodes clustering to enable scaling. Aelf joied as one of Theta’s private presale supporters and a long-term strategic partner. Aelf has decided to partner with Theta to create a new era of decentralized video media on the blockchain because of Theta Labs’ established ecosystem and technology leadership in the esports and media industry. Aelf will not only support Theta in the form of a joint partnership, but also initiate a long-term technology and marketing collaboration with Theta.
ZMT Capital
ZMT Capital is a technology driven investment firm focused on Fintech, Mobile, Hardware, AI, Blockchain and Cryptocurrencies.
Synapse Capital
Synapse Capital is a crypto asset investment firm implementing a hybrid venture/hedge strategy.
Network Statistics
Sliver.tv statistics (August 26th, 2019):
The information is taken from Similarweb.com
Use case
Theta Network aims to create a more efficient way to deliver all types of video-content in an incentivized, global, peer-to-peer mesh network. The company’s mission is to leverage blockchain technology to create the first Decentralized Video Streaming and Delivery Network whereby video viewers are incentivized to share redundant computing and bandwidth resources to address today’s video streaming challenges.
Specifically, viewers around the globe can contribute their devices as “caching nodes” whereby they form a video delivery mesh network that is responsible for delivering any given video stream to viewers anywhere around the world optimized for local. First, viewers’ devices are geographically much closer to each other than to the CDN POPs. This reduces packet round-trip time and improves the stream delivery quality, and thus addresses the “last-mile” delivery issue. Second, with a sufficient amount of caching nodes, most viewers will receive the stream from caching nodes, which will help streaming sites reduce their CDN bandwidth cost. Third, caching nodes also reduce round-trip time making foveated and next generation streaming technology practical.
To encourage viewers to contribute their computing and bandwidth resources, the team introduces the Theta token as an incentive mechanism. Caching nodes can earn tokens as they relay video streams to other viewers. Not only does the Theta Token motivate viewers to join the network as caching nodes, it also greatly improves the streaming market efficiency by streamlining the video delivery process. Within the Theta Network, advertisers can also directly target viewers at a lower cost, viewers earn Theta Tokens for their attention and engagement with their favorite content, and influencers earn Theta Token as gifts directly from viewers. More interestingly, streaming and content platforms can open up new and incremental revenue opportunities with Theta.
The full launch of the Theta protocol introduces a new blockchain and a native token structure where:
- Caching nodes earn tokens for caching and relaying video streams to other viewers
- Viewers optionally earn tokens from advertisers as engagement rewards, and can in turn gift to favorite influencers and content creators
- Streaming sites and platforms can drive incremental new revenues through sales of premium goods and services, and deepen user engagement through Theta
- Advertisers fund advertising campaigns with tokens to support influencers, streaming sites and viewers
- Streaming sites and platforms can offload up to 80% of CDN costs
Social metrics
GitHub metrics:
Theta has 8 public repositories and 15 private repositories. Overall, the Project has frequent commits to the collection of repositories.
Developer activity (from Coinlib.io):
The Theta management team believes the launch of the Guardian node Onboarding Program as well as the upcoming Universal Edge Caching nodes would give them an edge in community development.
Social media activity:
Official Telegram group — Discussions on price, possible partnerships, etc.
Bitcointalk.org — since November 23rd, 2017. Discussion on mainnet launch, price, roadmap.
Markets and volume
Theta Token:
Information from Coinmarketcap.com:
Information from Etherscan.io:
Information from Coinlib.io:
Theta Fuel:
Information from Coinmarketcap.com:
Information from Coinlib.io:
TA
Theta/BTC pair is currently testing support and general altcoin market trending lower we think new lows are incoming.
Competitors
Well-known traditional video streaming services — Twitch, Youtube, Hulu, Netflix, etc. can be considered as Theta’s potential competitors.
Relative to Peer5 and other non-blockchain content delivery network competitors, incentivization makes Theta unique in creating a robust community-driven P2P network.
The project is competing in the peer to peer video service space. Following projects are Theta’s blockchain competitors:
Key Comparables — Peer to Peer Video Service:
Key differentiating factors of THETA when compared to its competitors include:
- The project is on mainnet stage.
- SLIVER.tv, with 3MM monthly active users (“MAU”), as first app built on Theta. More than 500,000 users have shared bandwidth on SLIVER.tv, with corresponding microtransactions taking place on Theta testnet blockchain.
- Partnerships with live testnet channels with Samsung VR and MBN.
Roadmap
Theta has been on time for most communicated milestones. The team explains the two late milestones as impacted by the partnerships with Samsung VR, MBN, and CJ Group, which were very resource-demanding.
2019 Q3
- Launch support for video on demand (VoD) in Theta Mesh Streaming Network
- Launch guardian node functionality and onboard initial group of community-run guardian nodes
- Beta release support for Android-based set-top boxes and smart TVs
- Introduce guardian nodes into the validator node set on rotating basis
- Launch smart contract support
2019 Q4
- Expand Theta content delivery beyond video to support all forms of data (e.g. file updates, game patches, video ads, audio/music, etc)
2020+
- Power global data content delivery including static and dynamic web content
Token Mechanics
A Dual Currency System
In the interest of securing the network, installing proper governance, and managing the usage of the network, the Theta blockchain will use a dual currency system. The Theta token is used to stake, secure, and govern the Theta Network, while individual operations (video segment transactions, smart contract operations, etc.) is paid for with the operational token, Theta Fuel.
There are two key reasons for a dual currency system:
- First, this allows the utility and purpose of each token to be separated. THETA is used strictly for staking and securing the network, while TFuel is used to power utility-based operations of the network. This is necessary because staking inherently decreases circulating supply, but video segment transactions and smart contracts will require a highly-liquid token that can facilitate millions of daily transactions.
- Second, two tokens are needed to solve possible consensus issues that arise from using the same token for staking and operations. Because the token used for operations must be liquid, it would be easier for a malicious actor to accumulate a significant number of that frequently-traded token on the open market. If that same token is also used for staking, they could potentially threaten the security of the Theta Network. By separating the two functions (staking and operations) into different tokens, that risk is greatly decreased.
Theta Token Supply and Mechanics
Theta Token (THETA): The governance token of the Theta protocol. THETA is used to stake as a Validator or Guardian node, contributing to block production and the protocol governance of the Theta Network. By staking and running a node, users will earn a proportional amount of the new TFUEL generated. The supply of THETA is fixed at 1 billion and will never increase.
Theta Fuel Token Supply and Mechanics
Theta Fuel (TFUEL): The operational token of the Theta protocol. TFUEL powers on-chain operations like payments to relayers for sharing a video stream, or for deploying or interacting with smart contracts. Relayers earn TFUEL for every video stream they relay to other users on the network. You can think of Theta Fuel as the “gas” of the protocol. At Mainnet launch on March 15th, TFUEL was created as a native token on the Theta blockchain.
Validator and Guardian Nodes
In Theta’s Multi-Level BFT consensus, 10–20 Validator nodes make up a smaller committee to produce and validate new blocks to be added to the Theta blockchain. Guardian nodes are a second node type that make up a “second line of defense” of up to 1,000s of community-run nodes that download and examine the Theta blockchain and try to reach consensus on finalized checkpoints.
The name “Multi-Level BFT consensus mechanism” reflects the fact that the Validator/Guardian division provides multiple levels of security guarantee. With thousands of nodes, it is substantially more difficult for attackers to compromise blockchain integrity, and thus the blockchain has a much higher level of security. The design is aimed to achieve a good balance among transaction throughput, consistency, and level of decentralization.
Validator and Guardian nodes stake THETA and participate in block production and transaction processing. In return they earn TFUEL, which powers bandwidth/video relaying. Video platforms demand TFUEL and provide it to their users to allow video relaying on their platform. Relayers earn TFUEL as a reward for relaying, and spend it back on the video platform for premium content, subscriptions, etc.
Validator nodes have a minimum stake amount of 10,000,000 THETA (~1 146 570$) and will originally be run by Theta Labs, with close partners and video platforms to follow. Later in this year, when the Guardian node functionality goes live, some Validator slots will be filled by community-run Guardian nodes on a rotating basis.
The minimum number of tokens to operate a Guardian node is 100,000 THETA (~11 465$). The team states that having a relatively high minimum token requirement for nodes would enhance security, as it makes attacks expensive.
The supply of TFUEL token will grow by a rate per year set at the protocol. The initial target is a 5% annual increase in supply, which can be adjusted by protocol consensus. The new supply from each block will be distributed to each Validator and Guardian node on a stake-weighted basis. For instance, if a node stakes 5MM out of a total 500MM staked THETA, it will earn 1% of the new TFUEL generated each block.
Block rewards for Guardian nodes are distributed every 50 blocks (~5 min) since that is the block finalization interval. There is no difference between the stake-weighted amount of rewards for Validator nodes and Guardian nodes; both earn according to their proportion of stake versus total amount of THETA staked in the protocol. By virtue of the large minimum requirement of tokens, Validator nodes will earn much more in TFUEL rewards in nominal terms. There are no tiers to rewards earnings aside from the aforementioned differences.
Read more on the Guardian Node onboarding program check out user requirements to run a Guardian Node here.
The Theta Pre-Guardian Node program is an early preview of Guardian Nodes, the 2nd layer of nodes in Theta’s multi-BFT consensus mechanism.
While Guardian Nodes won’t go live until the end of Q3 2019, the Pre-Guardian Node (PGN) client is an early precursor that serves three important purposes:
- Theta token holders can start earning TFUEL, the payment token of the Theta protocol
- It allows the Theta team to gauge interest in users running Guardian Nodes, and identify the users most dedicated to running nodes
- It raises awareness for the Guardian Node program and the Theta project in general, which will drive more users running GNs when they go live
The latest Pre-guardian statistics for the month of June:
More than 670 active users are running the PGN client, totaling more than 100M Theta Tokens (10% of total token supply).
A few days ago, Theta partner and investor, Blockchain Ventures, has completed deployment of the first enterprise validator node on the Theta Network. By staking 2M of their own Theta Tokens, Blockchain is directly contributing to the Theta blockchain’s network security. Blockchain Ventures is the first of several enterprise validator nodes that will be coming online in the near future. The 2nd and 3rd enterprise validator nodes are also on the way, which will be run by two publicly-traded global companies. Also, the team is working with the Theta community to launch the first batch of guardian nodes. These nodes will be run by the Theta community and form the second layer of security in the Theta Network, and contribute to network consensus by finalizing blocks. Next week the team will release an update with more detail on how guardian nodes will operate and their release as part of a larger Theta Mainnet 2.0initiative.
Token Metrics
Key Metrics:
Token Name: THETA
Token Type: ERC-20 at TGE
Private Sale Allocation: 30% of Total Supply
Token Sale Date: 26 Sep 2017 to 27 Dec 2017
Token Sale Price: $0.067
Amount Raised: $20.0MM
Total Supply: 1,000,000,000
Token Supply Distribution:
Private sale tokens made up 30% of total token supply (no lock-up period).
Team was allocated 7.49% of total tokens issued (unlocked in Jul 2018).
Advisors received 1.23% of issued tokens (no lock-up period).
Partners received 12.5% of issued tokens (no lock-up period).
Network Seeding received 12.5% of issued tokens (no lock-up period).
Labs Reserves constitutes 36.28% of issued tokens (unlocked in Jan 2019).
Private Token Sale:
Conducted on 26 September 2017 to 27 December 2017 for 300,000,000 THETA and raised a total of $20.0MM at ~$0.067 per token, selling 30% of total token supply.
Token Governance
Theta’s tokens are held at the corporate level and governed by the Theta Labs board of directors. All tokens are held in cold storage in hardware wallets.
THETA Token Release Schedule
The following chart represents the number and breakdown of all THETA tokens that are to be released into circulation on a monthly basis.
Summary
Team: Mainly consists of tech specialists of different level, who used to develop streaming video applications. Most of the team members works for SLIVER.tv.
Idea: Decentralized video streaming and delivery network.
Development stage: Mainnet.
Whitepaper: Well composed, but outdated (token mechanics). Last updated on November 11th, 2018. No information on token allocation.
Roadmap: Theta has been on time for most communicated milestones.
Video traffic will account for 82% of all Internet traffic by 2022. Considering Internet traffic is expected to reach 4.8 zettabyte, that’s just under 4 zettabyte for video alone. However, the current infrastructure doesn’t allow viewers to take full advantage of the latest video technologies. Everything is too centralized, and content creators lose out as a result. Theta provides a decentralized video streaming platform that has the ability to solve these problems for both viewers and content creators.
But does Theta look like a high potential idea to revolutionize the video streaming world and not another “Twitch on the blockchain”?
For now, Theta is more like an additional platform for monetization for content makers from traditional video services and their viewers. It’s main competitor Twitch takes a 50 percent cut from streamers and has 944.5M monthly visits in comparison with 3.71M on SLIVER.tv, as the first app built on Theta. And, it is basically the same audience. From this point of view, the project needs more collaborations with content creators and advertisers to succeed. The excellent partnerships with live testnet channels with SLIVER.tv, Samsung VR and MBN the project has managed to earn in a short period of time already became Theta’s crucial advantages.
And there are more interesting things being planned after the network is launched, including shared mining rewards to distribute rewards among several users; anti-piracy measures to dis-incentivize piracy; and the inclusion of a general service platform that goes beyond streaming videos, but provides such services as smart streaming contracts, and the Guardian Nodes will go live until the end of Q3 2019. Theta’s incentive mechanism for a decentralized video streaming and delivery network still could be very disruptive.
