What is V SYSTEMS' Sidechain Mode?
Mainchain-Sidechain Model The platform introduces its own model for mainchain and sidechain. A blockchain S is called a sidechain of another blockchain M, the mainchain, if S satisfies:
• Awareness: full nodes of S are also full nodes of M and process the entire blockchain of M
• Synchronization: S observes abstract clock synchronization to M
Abstract clock synchronization deals with the ordering of blocks between the two blockchains. Imagine the blockchain as an abstract clock, whereof each block in the chain is a clock tick. It is called abstract as it has nothing to do with the local timestamps written into the blocks. Timestamps are local values that cannot determine the correct ordering of events globally. Instead, block number inside blockchain can determine a global time sequence. Observers can safely say events in a previous block always happen before events in a later block regardless of their timestamps.
When a sidechain block is generated, it links to the latest mainchain block as its mainchain parent. Multiple consecutive sidechain blocks are allowed to share the same mainchain block as their mainchain parent. This mainchain-sidechain parent-child relationship must also be order-preserving.
This model of mainchain-sidechain allows us to develop a proprietary communication method between the two blockchains. Unlike Blockstream’s proposal, our model does not require pegging on sidechains, thus giving sidechain projects much more freedom to innovate.