Vitalik Buterin, co-founder of blockchain platform Ethereum, posted a paper on a new kind of consensus algorithm last week. This algorithm requires only 1% of the nodes to be honest for the network to be secure. This results in 99% fault tolerance, increasing the security greatly.
How can Ethereum achieve 99% fault tolerance?
The new consensus algorithm introduces a new kind of validator nodes—“independent observer nodes”. These observer nodes observe the chain in real-time to filter any inconsistencies in the network. This original idea was published in 1982 by Turing award winning computer scientist, Leslie Lamport. The new algorithm to be implemented in Ethereum is Vitalik’s attempt to reformulate Leslie’s algorithm in a simplified form.
The new algorithm adds one’s own signature as a bump on the timeout of a message. This ability guarantees that an honest node saw the message on time. This can ensure that every other node sees the message on time as well. The definition of on time increments more than the network latency with every added signature. On implementation, the algorithm will render 51% attacks useless.
What are the benefits?
Ethereum developer, Conrad Barski states that there are several benefits of introducing this new protocol:
“Usually, all blockchain consensus[algorithms] care about is what the validators (i.e. miners) of a chain do. Vitalik is proposing that if an independent observer of the network traffic (i.e. just the blockchain client a user is running, not a miner/validator) watches what’s happening in real time and pays attention to when messages appear, they can detect ‘foul play’ by miners performing a 51% attack and this can provide additional safety guarantees that can protect against such an attack. This is somewhat similar to how merchants are already checking for 51% attacks themselves, only Vitalik’s version is more large-scale and complex.”
As of now, the Ethereum blockchain works on proof-of-work (PoW). This new protocol is expected to be set in action when Ethereum is shifted to proof-of-stake (PoS). The exact timeline for the PoS switch is not known, it might happen next year. In PoS, the more the number of coins/tokens a user has, the greater is his/her mining capacity. PoS will reduce the Ethereum reward by 80%; 0.6 ETH from the existing 3 ETH per block.
With the implementation of this consensus network, Ethereum might become the most secure blockchain network in the public domain.
You can read Vitalik’s paper for a detailed explanation of the implementation.