Cross-chain Technology: Taking Cross-chain Technology of Jingtum SWTC Public Chain as A Case
No man is an island entire of itself; every man is a piece of the continent, a part of the main
— — John Donne
Abstract
At present, most blockchain projects are running on their own islands. In other words, the interoperability between blockchains greatly confines blockchain application space. To connect each island, cross-chain technology plays a significant role of realizing the valued Internet.
Cross-chain technology refers to the technology that can transform assets on a specific blockchain into assets on another one, so as to ensure correlation of values between chains.
Status Quo
In the current blockchain world, various public chains, alliance chains and private chains will generate digital assets, and smart contracts on the blockchain will also generate a great amount of data.
From the perspective of public chain, the complex data exchange between chains is in need of authentication and transaction through cross-chain technology. Blockchain can be used as a chained database to ensure the non-tampering of data and promote the real-time establishment of data trust.
Most public chains transfer and transact assets depending on the private key control mode, so it becomes very complicated to set up authority management in cross-chain. In addition, in the centralized institutions cooperating with blockchain, enterprise keys and private keys are often controlled by an authorization management system in the centralized system. Enterprise servers are often protected by firewalls. Once a p2p network is set within the firewall of survival system, security holes will then be caused.
From the perspective of business, increasing DApps drive business interests towards cross-chain technologies. In the value network, more effective nodes and wider distribution will trigger a greater possible value accumulation. Cross-chain technology will support the valuation of the network as a “linker”.
Cross-chain Technical Approach
We have to pay attention to several issues to achieve cross-chain technology for two independent and relatively closed systems. How to verify transaction status on the original chain? How to transfer information with accuracy and in time? How to complete the transaction confirmation on another chain? How to prevent repeated payment?
From the technical view, it can be divided into following ways which have no dependency relationship and are often used according to different situations in practice.
The first is Notary Schemes. It verifies that a cross-chain operation or transaction is valid by having one or more centralized nodes as notaries.
The second is Sidechains / Relays. The sidechain mechanism is to realize Two-way Peg, which can utilize multiple signatures or hash locking. Relay mode is mainly one-way cross-chain from one chain to another, that simply, relays update information from one chain to another.
The third is Hash-Locking, which is a technology relatively easy to implement. It is originated in the HTLC (Hashed TimeLock Contract) and ensures the atomicity of cross-chain interactive operation.
The fourth is Distributed Private Key Control. Private assets are mapped to the built-in asset template on blockchain based on protocol through distributed private key generation and control technique. New smart contracts are deployed based on cross-chain transaction information so that new cryptocurrency assets can be created.
The fifth is Notary schemes+ Sidechains Mixing technology. Ether Universe is the world’s first cross-chain service platform based on the third-generation blockchain platform EOS.IO. The technology refers to an innovative scheme that achieves efficient communication by sidechains and carries out quick value exchange by notary mechanism.
Origin
Early cross-chain technologies represented by Ripple and BTC Relay focused on asset transfer. Current cross-chain technologies represented by Polkadot and Cosmos, focus on cross-chain infrastructure.
Since emergence of MOAC, WeiDex and other new technology, innovation of cross-chain technology is not confined as a simply way and has presented a tendency to develop as mixed solutions. As present, cross-chain technology is still in the preliminary exploration stage. A stable system has not yet been formed and there are still many problems to be fixed and improved.
Cross-chain technology appears in the Interledger Protocol published by Ripple in 2012, that firstly proposed a cross-ledger interoperability scheme to implement cross-ledger transfer through notary mechanism.
In 2013, Blockstram, a bitcoin community, firstly proposed a cross-chain sidechain scheme to realize circulation between parent blockchains and sidechains through Two-way peg. In October 2014, sidechain agreement is published in the white paper “Enabling Blockchain Innovations with Pegged Sidechains”.
Based on the theory and technology of sidechains, the Tendermint team first proposed the concept of cross-chain in 2014.
In 2015, the Lightning Network was launched to implement the quick transaction channel under the bitcoin chain through Hashed Timelock.
In 2016, BTC Relay white paper was released to realize one-way connection of bitcoin to ethereum based on cross-chain Relay.
In 2017, Polkadot and Cosmos proposed a cross-chain infrastructure relay platform. In the same year, Wanchain and Fusion proposed the cross-chain technology of distributed control authority management.
In December 2017, the Lightning Network was officially launched on the main bitcoin network and completed its first transaction.
Application Scenarios
Cross-chain technology has been gradually applied in financial scenarios such as cross-chain asset mortgage, trusteeship, lending, derivatives, etc. For example, the assets of Chain B are acquired through mortgage assets of Chain A, and users can get back the mortgage assets of Chain A it the assets of Chain B are returned successfully at maturity. On the contrary, Chain B has the right to freely dispose of Chain A mortgage assets. Decentralized exchange platform is one of the typical scenarios of the early implementation of cross-chain technology.
With continuous improvement of blockchain technology, cross-chain applications will develop from single to diversified development. Cross-chain technology will also be gradually applied to cross-chain smart contracts, multi-platform DApp deployment, cross-chain communication oracle, etc. The technology can help achieve the interaction of information within and outside the chain, that is to complete transfer and sharing of cross-chain information, and realize the commercial value of blockchain.
With the advent of 5G era, the Internet of Things is likely to break the boundaries between people, people and information, information and things, and gradually develop to chain everything. Among them, the cross-chain technology between machines will also come true.
Case Study: Cross-chain Technology Based on Jingtum SWTC Public Chain
Jingchang, an important part of Jingtum SWTC Public Chain ecosystem, develops digital asset decentralized cross-chain exchange technology based on the underlying layer of Jingtum SWTC Public Chain, and takes this as implementation of the cross-chain technology to establish the “Weidex Decentralized Digital Asset Exchange Platform” on the public blockchain.
On May 31st, 2018, cross-chain exchange functions of ETH and ERC20 launched and solved the barrier of token exchange between different public chains in reality. It made a big step forward in cross-chain exchange technology of digital asset decentralization.
The current phase of the cross-chain technology solution of Jingchang Digit is based on Jingtum SWTC Public Chain, that automatically monitors tokens of all other blockchain underlying systems through smart contracts and maps them to Jingtum SWTC Public Chain. With special order function on the public blockchain, compared with mode of order off chain and transaction on chain in other decentralized asset exchange platforms, Jingchang cross-chain exchange technique has the following four advantages:
- Security
Compared with Distributed Private Key Control, Jingchang cross-chain technology ensures that users can order, match and trade directly on the chain without contracting or saving user private keys. The private key of users’ wallet is only saved by themselves and the platform cannot get to and save it. In this way, the platform cannot use users’ token, even if the transaction platform is attacked. Because users’ token assets are on blockchain, the attacker cannot obtain the users’ private key and the token assets are always safe.
2. Trustworthiness
Since users’ order and transaction are completely carried out peer-to-peer on chain, all actions can be inquired on the blockchain network, that can avoid the risk of the traditional centralized transaction platform manipulating the price with false transactions. It ensures the authenticity of information.
3. Sharing
The technology shares market depth and flow. Because all of the users’ order, match and transaction are carried out on Jingtum SWTC Public Chain, all users (including different transaction platforms) who use Jingchang cross-chain technology for trading can share market depth and flow on chain.
4. Intelligence
Multi-exchange, multi-token and multi-party automatic transaction can be implemented.
Examples:
When the order 1VCC is sold at the price of 50UST, but there is no appropriate price in the existing VCC/UST transaction of Exchange A, the system will automatically match the transaction pairs and complete two transactions which meet the transaction conditions (that means the transaction price will be the best obtainable price)
a. Sell 1VCC on Exchange A and get 10000SWTC；
b. Sell 10000SWTC on Exchange B and get 55UST；
C. The final transaction price of original order is that selling 1VCC gets 55UST.
In addition, according to transaction inefficiency of former decentralized asset exchange platform, Jingchang Technology can provide no less than 2000tps processing speed based on Jingtum SWTC Public Chain. It can satisfy users’ transaction experience and all transactions on chain are tamper-resistant, as as to provide users a secure and fair exchange environment and promote popularization and application of digital asset Intervalue technique.
