Recent two years, with the fiery development of the blockchain, a large amount of capital has flowed into it. Industries involved in blockchain technology research and application development have mushroomed. from the current status of the blockchain market, the current blockchain project cannot really serve commercial applications. In addition to the limited blockchain capacity and slow transaction confirmation, what’s more, a single blockchain project is an independent value network with a problem of network isolation. The difficulty of cooperating between different blockchain projects greatly limits the space for the use of blockchain projects. Therefore, how to implement cross-chain technology and multi-chain integration has become one of the hot spots in the current blockchain research.
01. The overview of the cross-chain technology
Currently, There exist three cross-chain technologies: Notary schemes, sidechain/relays, and hash-locking.
Notary schemes: In Notary schemes, a group of credible nodes act as notaries to verify whether a specific event has happened on Blockchain Y and prove it to the nodes of Blockchain X. Interledger proposed by Ripple Lab is a representative of Notary scheme.
Sidechain/relays: If Blockchain X enables to verify the data coming from Blockchain Y, Blockchain X is called a sidechain. Sidechains are usually based on tokens anchored on a certain blockchain, while other Blockchains can exist independently. Existing sidechain projects are unable to construct cross-chain smart contract and support all kinds of financial functions, which is the reason that these Blockchain projects fail to make progress in the realms of stock, bond, and financial derivatives markets. The famous bitcoin-sidechains include BTC Relay (proposed by ConsenSys), Rootstock and ElementChain (Proposed by BlockStream), and the other sidechains, not for Bitcoin, include Lisk and Asch. Relay chain technology temporarily locks a number of tokens of an original Blockchain by transferring them to a multi-signature address of the original Blockchain, and these signers vote to determine whether the transactions happen on the relay chain are valid or not. Polkadot and COSMOS are representative relay chain technologies.
Hash-locking: Hash-locking is a mechanism to carry out payment by locking some time to guess the plaintext of a hash value, which derives from Lightening Networks. However, hash-locking supports a limited number of functions. Although it supports cross-chain asset exchange and cross-chain asset encumbrance in most scenarios, it is not usable for cross-chain asset portability and cross-chain smart contract.
The comparison of these three Cross-chain technologies is shown in Table
Cross-chain technology advantage comparison
InterValue as a project for the purpose of value interconnection, it contains two layers f meaning in value interconnection. In addition to the value interconnection between users from the InterValue platform, the value interconnection between different blockchain projects should also be achieved. This will eventually change the separate “island” situation between current blockchain projects and realize ubiquitous value interconnection.
02. InterValue multi-chain integration
InterValue adopts Full-node adapter multi-chain merging technique to connect different Blockchains. Specifically, as the unified entrance, InterValue uses the full node merging adaptor to trigger the transactions on the external subnet (BTC, ETH). The local full node network is composed of an external subnet and an internal subnet. The external subnet mainly includes other chain networks, such as BTC, ETH and so on. The internal subnet mainly includes the piecewise network of InterValue. The top-level network is mainly composed of higher nodes of all nodes
Full node fusion adapter cross-chain integration
The multi-chain fusion adapter is deployed on the full node as part of the function of the cross-chain communication module. The full node triggers the transfer operation of the local node’s external subnet to realize the role of the transfer agent.
03. InterValue Cross-chain communication
InterValue is not only a self-contained Blockchain network but also a bridge to support cross-chain
communication functions, such as cross-chain asset exchange and cross-chain asset portability. By using the InterValue platform, anyone can develop financial applications in accordance with the requirements of application scenarios. The basic idea of the InterValue cross-chain technology is adopting relay chain thoughts and implementing the cross-chain communication module as a full node overlay layer over the basic chain of InterValue. In this technology roadmap, we not only keep the independence of cross-chain interoperability but also reuse all kinds of functions offered by the basic chain of InterValue
Intervalue cross-chain communication and cross-chain integration architecture design
The cross-chain communication module of InterValue includes three types of nodes: verification nodes, block-aware nodes and merging nodes.
Their respective functions are listed as below:
1. The verification nodes are the notary nodes in the basic chain of InterValue. They verify the validity of data coming from some original Blockchain and construct new blocks in InterValue. The verification nodes have to mortgage enough asset to guarantee that they will do their jobs loyally.
2. The block-aware nodes help the verification nodes to gather valid cross-chain communication block. These nodes, similar to the miners in PoW, run a full client of some original Blockchain, construct new blocks and execute transactions. After receiving cross-chain transaction request blocks, the block-aware nodes pack these request blocks and send them to the verification nodes.
3. The merging nodes act as the gateway between InterValue and another original Blockchains. Each merging node has two queues which respectively handle incoming transactions and outgoing transactions. In addition, the merging nodes should have some tokens of original Blockchains and support cross- chain Oracle.
04. Summary
The Blockchain is the core infrastructure of the value network space. Its application should not be limited to and stop at the application of the alliance chain, it will be circled in a small range, InterValue’s cross-chain technology, and multi-chain integration, to different areas. The connection and expansion of the Blockchain will realize various underlying network protocols of the value transmission network, construct a global value Internet, and provide a basic network for various value transmission applications.