@btcfork 13 May 2021 edited more from that month

Summary of Bitcoin Cash upgrades up to May 2021

It is well understood by now that Bitcoin Cash is the version of Bitcoin that upgraded the block size limits in order to scale its capacity on chain. Throughout its life since 2017, Bitcoin Cash has done a number of successful system upgrades, with another one scheduled for May 2022. In this short post, I want to give you a summary overview of these upgrades. This information is compiled from https://upgradespecs.bitcoincashnode.org/ . **It is important to remind that** ****not every Bitcoin Cash upgrade is a**** ****hard fork******. Some upgrades, like the past May 2021 one, do not include any changes that can result in a fork.** https://en.bitcoin.it/wiki/Hardfork *I wish read.cash would allow nice tables in its markup language, but currently it doesn't. So I have to include a graphical table here, suitable for copying to other platforms, and the textual form where the hyperlinks work, at the end.* Bitcoin Cash (BCH) network upgrades - graphical summary

Bitcoin Cash (BCH) network upgrades - textual summary **August 2017** **(original UAHF)** https://upgradespecs.bitcoincashnode.org/uahf-technical-spec/ Maximum block increased by a factor of 8 (from 1MB to 8MB) Other basic scaling parameters (max txs in block, max sigops per block) adjusted to scale with block size Added replay protection Difficulty adjustment in case of hashrate drop (EDA) Added new service bit (NODE_BITCOIN_CASH) Enforcement of stricter transaction validation (SCRIPT_VERIFY_STRICTENC) November 2017 https://upgradespecs.bitcoincashnode.org/nov-13-hardfork-spec/ New difficulty adjustment algorithm (DAA) Enforcement of LOW_S signatures (BIP 0146) https://github.com/bitcoin/bips/blob/master/bip-0146.mediawiki#low_s Enforcement of NULLFAIL (BIP 0146) https://github.com/bitcoin/bips/blob/master/bip-0146.mediawiki#nullfail May 2018 https://upgradespecs.bitcoincashnode.org/may-2018-hardfork/ Blocksize increased by a factor of 4, to 32MB (original Satoshi client blocksize) Increase OP_RETURN relay size to 223 total bytes Re-enabling of several opcodes https://upgradespecs.bitcoincashnode.org/may-2018-reenabled-opcodes/ Added “automatic replay protection” (ARP) (fork off old versions in next upgrade) November 2018 https://upgradespecs.bitcoincashnode.org/2018-nov-upgrade/ Enforce canonical transaction order (CTOR) New opcodes: OP_CHECKDATASIG, OP_CHECKDATASIGVERIFY Enforce minimum transaction size Enforce "push only" rule for scriptSig Enforce "clean stack" rule May 2019 https://upgradespecs.bitcoincashnode.org/2019-05-15-upgrade/ Enable Schnorr signatures Allow Segwit recovery https://upgradespecs.bitcoincashnode.org/2019-05-15-upgrade/#allow-segwit-recovery November 2019 https://upgradespecs.bitcoincashnode.org/2019-11-15-upgrade/ Enable Schnorr signatures for OP_CHECKMULTISIG(VERIFY) Enforce minimal push and minimal number encoding rules in Script May 2020 https://upgradespecs.bitcoincashnode.org/2020-05-15-upgrade/ Replace SigOps counting system with a new system (SigChecks) New opcode: OP_REVERSEBYTES Increase unconfirmed chain length limits from 25 to 50 November 2020 https://upgradespecs.bitcoincashnode.org/2020-11-15-upgrade/ Replace DAA with new difficulty adjustment algorithm: ASERT https://upgradespecs.bitcoincashnode.org/2020-11-15-asert/ May 2021 https://upgradespecs.bitcoincashnode.org/2021-05-15-upgrade/ Removal of the unconfirmed transaction chain limit Allow multiple OP_RETURN outputs (but keep 223 byte limit for now) May 2022 (upcoming) https://upgradespecs.bitcoincashnode.org/2022-05-15-upgrade/ CHIP-2021-03: Bigger Script Integers https://gitlab.com/GeneralProtocols/research/chips/-/blob/master/CHIP-2021-02-Bigger-Script-Integers.md CHIP-2021-02: Native Introspection Opcodes https://gitlab.com/GeneralProtocols/research/chips/-/blob/master/CHIP-2021-02-Add-Native-Introspection-Opcodes.md [sponsors]