In the official blog post, Dash team has stated that they are working on an extraordinary LLMQ-based ChainLocks which will mitigate 51% attacks making Dash the first cryptocurrency offering a real-world solution rather than a suggestion.
What is a 51% attack?
A 51% attack on a blockchain refers to a miner or a group of miners trying to control more than 50% of a network’s mining power, computing power or hash rate. People in control of such mining power can block new transactions from taking place or being confirmed.
There are probably many more possible attacks/scenarios that all lead to some real damage thus making the further development of cryptocurrency an issue of survival.
How Dash Upgrades to Handle the Threat of 51% Attacks?
Despite the fact that Dash is as vulnerable as any other Proof of Work coin the introduction of LLMQ (Long Living Masternode Quorums)-based ChainLocks will enable Dash to implement a new protection mechanism against 51% mining attacks. This protection mechanism (ChainLocks) is proposed in DIP8.
This DIP has been in progress for a number of months and the team decided to publish it recently as an answer to community questions on how Dash is going to handle the threat of 51% attacks.
ChainLocks and Quorums in Short
ChainLocks have a few very important effects on the whole network and its economics. The most important effect for normal users and merchants is that transactions can be considered fully confirmed after the first on-chain confirmation inside a block protected by ChainLocks. This means that there is no need anymore to wait for 6 or more confirmations until a received transaction can be considered secure.
A quorum is a collection of entities that are able to vote on something. Every member is generally allowed to vote only once. If >= 51% vote for the same thing, the majority is reached. Something either got the majority of votes or not, there should be nothing in between.
This removes all ambiguity on a single node, including miners. It also reduces ambiguity on the whole network, as it also means that a transaction that is well propagated can’t be replaced by a conflicting one.
Not Every Coin Can Have ChainLocks
One of the main prerequisites required to make ChainLocks secure is a Sybil protected network of semi-trusted nodes. A coin that does not offer such a class of nodes will not be able to implement something like ChainLocks in a secure manner.
In Dash, the Masternode network is protected against Sybil attacks by requiring a collateral of 1000 Dash per Masternode.
With the current parameters that Dash target for LLMQs, an attacker would have to buy at least 60% of all Masternodes to get a realistic chance of success.
Such security enhancements have a positive impact not only on the Dash itself but also on the crypto community as a whole.
Great job, Dash.