This article briefly recaps the content of the MASS white paper. For further reading, we recommend visiting our website to access more articles and the original white paper.
Background
Before Bitcoin was created, people did not believe that tens of thousands of computing nodes distributed around the world could maintain a database on the Internet. The emergence of Bitcoin proved that a practical, Internet based Byzantine fault-tolerant system was feasible. Based on this, the first democratic digital currency in human history was issued. However, because Bitcoin uses a Proof of Work (PoW) consensus algorithm, which depends heavily on computing resources, Bitcoin and many other blockchain systems using PoW consensus algorithms have gradually evolved into centralized networks. They have become systems with resource oligarchs.
MASS believes that a more advanced consensus algorithm is the solution to promote the mass adoption of blockchain technology and realizing the vision of network decentralization. A consensus algorithm that is more democratic, fair, energy-efficient, safe, highly scalable and universal. Based on this vision, the MASS community has developed the MASS proof-of-capacity consensus protocol.
The MASS proof-of-capacity consensus protocol has many advantages; there are low barriers of entry, and it’s permissionless, with a 51% Byzantine fault tolerance, natural decentralization, and parallel support for multiple blockchains.
To complement this new consensus protocol, the MASS community has developed an innovative blockchain system; Mass Net has a novel design and robust economic mechanism, which can help the consensus engine network to perform a cold start.
The Principles of Proof of Capacity (PoC)
In the PoC consensus algorithm, when a node submits a block to the network, it must provide a valid proof of capacity. Without the corresponding storage size, it is difficult for a node to generate an effective proof of capacity. At the same time, any node in the network can verify the proof. If the block data and proof are valid, the rest of the network will accept the block.
The process of providing a proof is as follows. In the initialization phase, a series of hash data is generated according to the protocol and stored in the storage capacity. When a new block is being generated, data will be searched in the storage capacity based on the value of a randomly generated number. This data will then be used to generate a certificate and participate in the competition to generate the next block. The entire process includes five stages: initialization, block construction, block reception, main chain selection and penalty mechanism.
Initialization: Miners will first initialize the hard disk by generating two HashMaps in sequence, and then save the last one to the hard disk.
Block construction: After verifying the latest block timestamp, miners obtain challenge parameters from the latest block. They then find the data that meets the conditions in the HashMap, and generate a proof of capacity. If the quality of the capacity proof is greater than or equal to the difficulty of the entire network, the right to generate the next block is obtained. The miner signs the block hash and broadcasts the block to other nodes.
Block reception: After a node receives the newly generated block, it will perform a series of verifications, such as timestamp, public key, signature, capacity proof, proof quality, transaction legality, etc.
Main chain selection strategy: When multiple blocks that meet the above rules are received in the network, the main chain block needs to be selected according to certain factors; largest cumulative difficulty, smallest Timestamp, and best proof quality.
Punishment mechanism: The multi-mining penalty mechanism is used to resist multi-mining attacks. If the node receives the same proof in two different headers, it proves that the person in the block is double mining. The node can construct a penalty proposal so that the public key of the miner is added to the banlist, and the corresponding capacity becomes invalid.
Economic mechanism
All consensus mechanisms need to find some effective way to encourage growth and sustainable development; the MASS incentive mechanism makes the rational interests pursued by each participant consistent with the interests of the entire system, and enables a highly decentralized and stable consensus network.
The maximum supply of MASS (MASS Net’s cryptocurrency) is 206,438,400, which will be issued within 15 periods. After each period, the reward for each block will be halved. Furthermore, the length of the new period will be double the length of the previous period.
The halved block heights are as follows: 13440, 40320, 94080, 201600, 416640, 846720, 1706880, 3427200, 6867840, 13749120, 27511680, 55036800, 11087040, and 440388480. The block reward distribution method is as follows:
Hard disk mining (18.75%): Hard disk mining means that miners invest in hard disks, run mining software, and participate in maintaining network consensus. If a block is mined, 18.75% of the block reward will be obtained.
Staking (18.75%): Staking means that miners lock a certain amount of MASS cryptocurrency until it reaches a predetermined block height. The minimum lock-up period is 61,440 blocks (approximately 32 days), and the locked amount is at least 2,048 MASS. Only the top 30 staking nodes can be rewarded, and 18.75% of the block reward will be equally distributed to these 30 staking nodes according to the weight of the locked amount.
Game mining (62.5%): Hard disk miners can bind a certain amount of MASS to their capacity space. If their capacity space wins a block, they will receive 62.5% of the block reward; if the capacity space of the wining block is not bound with MASS, 62.5% of the block reward will go to the staking nodes.
The decision to choose game mining or hard drive mining depends on a miners confidence in the future of the MASS network. The dynamic between the different economic mechanisms at play for MASS’ various mining options will help the network develop smoothly.
Transactions
There are three main types of transactions in MASS Net: ordinary transactions, staking transactions and binding transactions.
Ordinary transaction: Transfers MASS cryptocurrency.
Staking transaction: Freezes the trading rights of MASS cryptocurrency to a certain block height, and unlocks it only after the block has reached the specified block height.
Binding transaction: Binds the MASS cryptocurrency to a capacity space address, and the right to use can only be restored after the unbinding transaction is submitted.
Advantages of MASS
Security: The PoC protocol uses the principle of time memory trade-off to ensure the unforgeability of the proof, and uses a verifiable random function to ensure that the MASS system has 51% Byzantine fault tolerance. In addition, the fork detection penalty scheme can protect the main chain from “Nothing at Stake” attacks that may split the main chain.
Fairness: The MASS PoC consensus protocol guarantees that the block generation probability of a node depends only on the proof of the effective capacity provided by the node. In addition, the proof of effective capacity is independent of storage media, so all nodes participating in the MASS network have similar marginal costs.
High efficiency and energy saving: In the MASS PoC protocol, computing resources are only needed when initializing storage capacity, and when entering the block consensus phase, data is accessed only once with O(1) complexity. Therefore, using the MASS PoC protocol for block negotiation does not require continuous power input consumption. When the MASS system executes block consensus, the computing resources used can be ignored and will not affect the normal use of the computer. When the storage capacity does not participate in the MASS network, it can be reformatted and used for other purposes.
General: In the consensus process, nodes only need to perform access queries on the initialized capacity without any data operations. Therefore, the same storage space can provide multiple capacity consensus proofs, and nodes using the MASS PoC protocol can simultaneously support multiple blockchains in parallel.
Summary
The MASS consensus engine, the MASS Net blockchain, and the MASS cryptocurrency are interdependent and are the three important forces in the initial stage of the MASS ecosystem.
The MASS Net blockchain system is the first public chain to utilize the MASS consensus engine, which uses the MASS cryptocurrency as its value anchor. The MASS consensus engine aims to be a fair and energy-efficient system by requiring only a small amount of computing resources, compared to incumbents like Bitcoin; PoC also doesn’t require specialized hardware, which enables more miners to participate in the network. Furthermore, the MASS economic mechanisms will help grow the MASS mining community, thereby providing a solid underlying consensus for future participants of the MASS ecological block chain.
Beginning in 2019, several projects have shifted from smart contracts to application chains. In the future, hundreds or thousands of application chains will form an application chain ecology, which requires the support of cross-chain technology. The MASS consensus engine is expected to solve cross-chain technical problems from the perspective of the bottom layer of consensus, which may introduce blockchain to a new chapter. MASS has a natural multi-chain feature; the same hard disk space can provide proofs for multiple chains that meet the same PoC consensus standard. MASS Net blockchain aims to become the basic infrastructure for all blockchain consensus layers.
