Consensus is a major element in ensuring the integrity of a blockchain. Participants need to always be in agreement as to which blocks are added to the chain, and any disputes need to be dealt with quickly otherwise forks can severely destabilise the chain.
For example, in a typical proof-of-work (PoW) style chain like Bitcoin, the prohibitive cost of mining will deter participants from splitting their hashrate (computational power) over different forks. But if a system has forked, with no clear winner immediately presenting itself, participants will be encouraged to withdraw from the system entirely, crippling it.
Velas is developing a platform that features an AI-enhanced consensus algorithm to eliminate common security issues plaguing blockchains and cryptocurrencies, such as the 51% attack or the nothing-at-stake problem.
The network adopts a delegated proof-of-stake consensus (DPoS) algorithm to prevent errant or malicious block formation. Rather than having blocks awarded according to hashrate, with the most powerful GPUs winning transaction fees, participants use their coin balance to elect a delegate (sometimes called a Witness) to act as a validator of new blocks.
The weight of an elector’s vote is determined by their stake in the system, such as how many coins they have (hence proof-of-stake). Delegates are tasked with upholding the integrity of the network, and hold their power only as long as the community votes them in.
However, Velas implements a version of this algorithm that uses an AI to decide which nodes should be considered delegates, or ‘Advisors’ as they are termed. Using a proof-of-importance algorithm, the Velas AI scores nodes according to their uptime, hashrate and coin balance.
Advisor nodes have the power to add new blocks, as well as to verify the integrity of blocks flagged as fake.
These measures will help prevent 51% attacks, where someone has to acquire control over 51% of all nodes to control the network, as Velas requires an 80% consensus to determine new blocks. Any actor with over 80% will already control the entire network and would simply be robbing themselves.