Nikolai Durov, a Telegram co-founder, authored a paper on February 3, laying out extensive details of Catchain. Catchain is Telegram Open Network’s consensus mechanism. The proposed solution in the paper is a (BFT) Proof of Stake (PoS) algorithm, which resembles the one used by Cosmos or NEO.
BFT algorithms are well designed solutions that try to solve the Byzantine Generals problem. In this case, the actors of a specific network are required to maintain their functionality. That strategy works even in cases where some of the nodes are malicious or unreliable.
How Does Catchain Work?
Catchain operates efficiently as long as 33% of the nodes are not malicious. That number equals the theoretical limit that is outlined for BFT solutions. The system primarily focuses on validating every block as it gets generated. This strategy is similar to Cosmos’ Tendermint or NEO’s dBFT.
This is resistance to systems proposed by Ethereum and Cardano, where the blocks are easy to produce, although they must be then reconciled through fork resolution. Every new block in this chain is created through a block generation round. During the generation process, validators have a limited time to agree. If no agreement is reached, the block is skipped.
Every validator has a specific role during a block voting process. Some of them create the blocks while others propose a block for voting. The remaining nodes vote on the proposal. These roles are shifted with every round to guarantee the correctness of the procedure.
Telegram is designed in a way that it does not have more than 100 validators for the master chain. In the case of every ‘shard chain,’ it required 10-30 validators. A block can be generated every five seconds, according to studies conducted in 2018. During these five seconds, the block undergoes the full consensus procedure every time.
The system is reported by TON developers to resemble Cosmos’ and Algorand’s for the most part. The differences exist in some specifics, like the way nodes communicate with one another. By just having a node communicate with each other is quite inefficient. Thus, every project tries to find its unique method of making the process faster.
In October 2019, the SEC prevented TON’s launch with emergency action. The commission states that Telegram conducted an unauthorized sale of securities. The other ecosystem participants say that since the sale was limited to just the accredited investors, Telegram did not do anything wrong.
For now, the network is active in testnet mode. That has not put off some entities from creating blockchain explorers for it. But the commission has nevertheless been quite critical of its state of development, commenting that there are few current and planned uses for its GRAM tokens.