Telegram’s co-founder Nikolai Durov lays out the details of Telegram Open Network’s consensus mechanism, named Catchain in his new white paper. The proposed solution is a Byzantine Fault Tolerant (BFT) built for Proof of Stake (PoS) algorithm.
BFT algorithms are attempted solutions to solve the Byzantine Generals problem, where actors of a particular network need to maintain its functionality even if some nodes are unreliable or malicious.
“Consensus protocol is a central part of any blockchain and it needs to be described for the further analysis of the blockchain and its code,” said TON Labs’ Mitja Goroshevsky Goroshevsky.
Telegram is set to have no more than 100 validators for the master chain and from 10–30 for each “shard chain.” According to tests conducted in 2018, a block can be generated every five seconds, undergoing the full consensus process. The protocol hasn’t changed since October 2019 before SEC’s litigation disrupted their plan to go live.
The consensus process will take a three-steps validation process whereby some validator nodes will create the block, others selecting the blocks for approval and the rest of the nodes voting for a block to be approved.
If the validators are not able to reach a consensus, then the round is skipped and the new block is not committed to the blockchain. If this goes on for a few rounds, new validator election can resolve the deadlock.
In its arguments filed with the court, the SEC has argued Telegram didn’t create a viable blockchain, as it promised to do. Telegram fought these allegations as irrelevant, saying, “It is the SEC’s burden to prove that Grams will be securities, not Defendants’ burden to prove their technology works.”