May 15, 2021

Schnorr signatures implemented in Bitcoin Cash network and transaction plasticity problem fixed

The planned hard fork took place on the Bitcoin Cash cryptocurrency network, as a result of which a full hard fork was added support for Schnorr signatures, a solution aimed at increasing transaction privacy.

Block number 609136 found by the BTC pool at 13:44 UTC on Friday, November 15th, was the first that older versions of Bitcoin ABC, including 0.19.0, were considered invalid. The new version of Bitcoin ABC 0.20.6 software, however, adopted it, thereby confirming a successful hard fork.


Implementation of Schnorr signatures will allow aggregationseveral signatures for one transaction into a single one due to linear mathematics embedded in the scheme. The same approach can be applied for multi-signature transactions: by combining public keys and signatures into “threshold public keys” or “threshold signatures”, such transfers can be made indistinguishable from ordinary ones.

Also with the latest Bitcoin Cash updateplasticity of transactions has been eliminated - the ability to change the transaction identifier (TXID) without canceling the transaction itself This problem has long been a considerable headache for developers of projects based on the Bitcoin blockchain. On the bitcoin network, it was solved by activating the Segregated Witness protocol in 2017.

At the same time, the update did not affect the complexity change algorithm, which is responsible for recalculating the mining difficulty of BCH based on the data of the last 144 blocks found.

Recall earlier researchers at BitMEX Researchcame to the conclusion that the increase in hashrate volatility in the Bitcoin Cash network in October could be due to the manipulations of individual players, although direct evidence of this was not found.