A recent proposal by Dash, ChainLock, combats one of the major issues in Proof of Work networks, namely 51% attacks. Simply put, blocks and transactions included in them are locked into the chain on a first come, first serve basis, thus guaranteeing no altering of that data can be done.
Are ChainLock and LLMQs the answer?
The developers of Dash have decided to employ Long Living Masternode Quorums or LLMQs to secure the network from 51% attacks. The goal is to have a pre-defined number of masternodes validating blocks as soon as they’re reported on the blockchain. Provided more than 60% of these designated masternodes see the block in question, they’ll validate it and lock it and the transactions onto the chain.
According to the official Dash blog post:
The idea of ChainLocks is to perform a verifiable network-wide measurement/vote of the “first-seen” rule.
To identify these types of blocks, they’ll have a special signature CLSIG which will be broadcasted onto the network to all other nodes and deemed valid as the longest chain. This way, there’s no incentive for miners to withhold solved blocks and create hidden chains to report them later on in an attempt to override the previous information.
Once a block is locked into place, any others that come after it, not carrying the CLSIG will be rejected by nodes on the network. This enables transactions to be fully confirmed after only 1 block, thus increasing the speed of the network.
The rules governing consensus in the network cannot be overridden. A CLSIG valid block still need to obey all the other rules of the blockchain, otherwise it will again be invalid. The whole process puts a lot of faith into these particular masternodes and could be seen as a slight move towards centralization, but according to the developers it’s a worthy trade-off.
What is a 51% attack?
The most common risk of fraud in a Proof of Work (PoW) network is the 51% attack. This is the case in which a single entity, whether a person or organization, owns more than 51% of the mining (calculating) power in a cryptocurrency network. Having this amount of influence, allows directing which transactions are approved or not, force new rules of consensus, alter block rewards and more.
As this drawback is one of the main issues when we speak about blockchain security, one could argue it’s a crucial factor to be solved in any PoW coin. Therefore, the developers of Dash have proposed a new take on combating this problem, namely ChainLock.
While an interesting prospect, so far, there’s no specific date set when this feature will be implemented. Rest assured, we’re going to cover it as soon as there’s information.