Bitcoin ABC
Amaury Séchet's “Adjustable Blocksize Cap” client, which launched Bitcoin Cash in August 2017 and became eCash's node after the 2020 split.
The wiki's angle: ABC is a rare case of a client becoming its own chain. It wrote Bitcoin Cash's first rules, lost the BCH ticker over its funding rule in 2020, and carried on as eCash.[6][7]
Origin
The first software implementation of the Bitcoin Cash fork was introduced under the name Bitcoin ABC during a conference in June 2017, the same month Bitmain called a bigger-block hard fork a “contingency plan”[1]. ABC stands for Adjustable Blocksize Cap[2]. On S17 E19, Amaury Séchet said ABC was its own fork of Bitcoin Core rather than a descendant of XT, Classic or Unlimited[3].
UAHF
ABC's user-activated hard fork specification set a default activation time of 1501590000, the median time past corresponding to 1 August 2017[4]. It required the fork block size limit to be configured to at least 8,000,000 bytes[4]. Alongside it, the Bitcoin Cash specification defined a SIGHASH_FORKID signature digest so that transactions could not be replayed across the split[5].
The 2018 and 2020 splits
In November 2018 the ABC camp, backed by Roger Ver and Jihan Wu of Bitmain, kept a 32 MB block size while the Bitcoin SV camp pushed 128 MB[2]. In November 2020 ABC's 8% coinbase rule split it from the rest of Bitcoin Cash, and its chain traded as BCHA before being renamed eCash[6].
References
- secondaryWikipedia, “Bitcoin Cash” [archived]
- secondaryWikipedia, “Bitcoin Satoshi Vision” [archived]
- episodeS17 E19: Amaury Séchet — Bitcoin ABC was its own fork of Core, not XT/Classic/Unlimited▶ listen at 56:35timestamp transcript-derived, pending a listen [archived]
- primaryBitcoin ABC / bitcoincash.org, UAHF technical specification (activation 1501590000) [archived]
- primarybitcoincash.org, “BUIP-HF Digest for replay protected signature verification across hard forks” (SIGHASH_FORKID) [archived]
- btkeCash (XEC): The Fork That Taxed Itself (BTCTKVR: Forks!) [archived]
- episodeS17 E19: Amaury Séchet — the funding dispute at the core of the 2020 split▶ listen at 2:26:25timestamp transcript-derived, pending a listen [archived]