Why Bitcoin Cash has signed up for Schnorr Signatures

Bitcoin Cash has beaten Bitcoin to the punch and implemented Schnorr Signatures first. Despite differing ideas, both versions of Bitcoin have agreed to this upgrade

Bitcoin Cash has beaten Bitcoin to the punch and has implemented Schnorr Signatures onto its platform first – something its supporters are keen to remind proponents of BTC.

However, the hard fork used to implement this upgrade didn’t quite go to plan, with a cyberattack seemingly taking place on the network. It has since recovered and is now working as normal.

Bitcoin and Bitcoin Cash have a heated history of disagreement, but both appear to agree on the benefits of Schnorr Signatures.

Why implement Schnorr Signatures?

Schnorr Signatures have been around since the 1980s. However, due to a patent filed on the cryptographic technique by creator Claus Schnorr, the usage of Schnorr Signatures wasn’t widely available until 2008 – coincidentally the same year as the birth of Bitcoin.

Schnorr Signatures are first and foremost a privacy update. Through Schnorr Signatures, people hope to reduce the ability of chain analysis companies to track or trace where your cryptocurrencies are coming from and going to. It is another step in the battle of keeping your cryptocurrency dealings and transactions private – a key tenant of the crypto-anarchy philosophy.

They also provide a slight scaling benefit, although for Bitcoin Cash which has scaled through bigger blocks, this is of less importance.

Taken from a core developer

Ironically, considering the vitriol between both the BTC and BCH camps, it was a Bitcoin core developer that presented the possibility of incorporating Schnorr Signatures onto Bitcoin.

Pieter Wuille was the developer to suggest the Bitcoin Improvement Protocol (BIP). However, due to BTC upgrading via a soft fork, the implementation takes more time. As BCH has chosen to upgrade via a hard fork, it can be achieved much faster. Since the split from BTC, BCH has chosen to hard fork once every six months for development updates in a similar way to Monero.

Although Wuille is both a Bitcoin core developer and a co-founder of Blockstream, there appeared to be little hesitance from the BCH community to use his ideas and implement Schnorr Signatures on BCH.

Due to the similarities in their respective blockchains, it is fairly easy for ideas on both chains to be applied to both cryptocurrencies.

The hard fork and attack

Although hard forks can be contentious, the upgrade for Schnorr Signatures wasn’t for Bitcoin Cash. This means that there is no split in the Bitcoin Cash blockchain, and once the upgrade is complete, things should run as normal.

However, soon after the hard fork occurred it became apparent that Bitcoin Cash was under attack thanks to research carried out by BitMEX. The attacker appeared to exploit a block template creation bug. This meant that 10 blocks of BCH went out empty. At the same time, a large short was placed on a trading website in the hope this attack would crash the price and the attacker could cash in on their short position. The attack didn’t work out as planned though.

Despite the attack, developers were quick to react and no lasting damage was done to the network other than some slight criticism from a few at the time.


The implementation of Schnorr Signatures onto Bitcoin Cash before Bitcoin has given BCH some bragging rights over its nemesis. With the upgrade not going quite as planned though, it hasn’t been smooth sailing. Fortunately, no lasting damage has been done to the Bitcoin Cash network and the issue was dealt with swiftly.

It will be interesting to watch the development race between the competing versions of Bitcoin moving into the future. Will they continue to use each other’s ideas or will they soon set off down completely different development paths?

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