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For a research project I'm trying to detect the major technical differences between Bitcoin and Bitcoin Cash. I know that BCH uses a larger block size and does not support SegWit. But what other differences are there?
I know this is a broad question - I'm looking for an overview only, not an exhaustive, detailed list.
In particular, but not exclusively, I'm interested in:
- Which features are only implemented in one of both chains?
- Do the data structures differ (blocks, transactions, inputs, outputs)?
- Is there a difference in which script instructions are supported?
- What about addresses and address types?
- Do both chains commonly implement the same BIPs or are BIPs usually exclusive to one chain? Is there a list of which BIPs are implemented in which chain?
- Overall, what's the best approach to track past and future changes in both chains? Can you recommend any resources on that issue?
Finding differences by looking at the code does not seem practical to me given the time it'd take me to pinpoint and understand all changes. I used git log --oneline master --reverse on both chains and diffed the results to get some insight, but it's still hard to detect changes that are relevant to me.
Maybe you want to group some of the items as sub-bulletpoints under segwit (malleability fix, quadratic hashing fix, and sig covers value are all mandatory fixes for segwit transactions; and there is also an address format for them called bech32, which cashaddr is based on). If you feel like listing who invented what, Blockstream should also be credited for the quadratic hashing fix, signature covers value, Schnorr signature specification, and the BCH-code based addresses. I don't think mottos or hearsay about decentralization count as technical differences. – Pieter Wuille – 2019-04-26T17:17:19.330
@PieterWuille Thanks pwuille, I had forgotten about a few of the SegWit's advantages, it seems much more neutral now. I've also made it community wiki. – MCCCS – 2019-04-26T17:28:58.770
Also what does the "not provably" mean? Third party malleability is clearly not possible for segwit inputs. – Pieter Wuille – 2019-04-26T17:31:51.680
1I've made a few changes, and changes the explicit authorship attribution to just mentioning what features are based on (as authorship is hard to attribute exactly). – Pieter Wuille – 2019-04-26T17:44:28.217
I might have misread "Provably no inherent signature malleability, while ECDSA has a known malleability, and lacks a proof that no other forms exist. Note that Witness Segregation already makes signature malleability not result in transaction malleability." (here)
– MCCCS – 2019-04-26T18:03:29.590Ah yes, that's right - but in SegWit that's not relevant anymore. – Pieter Wuille – 2019-04-26T18:05:14.790
Bitcoin: Compact Blocks, FIBRE, Satellite downlink. – Jannes – 2019-04-26T21:29:53.347
@MCCCS, from your answer it seems that "Has SegWit" is the only main feature added only to Bitcoin and all items below are a consequence (cost or benefit?) of SegWit? Most of the items in the Bitcoin Cash list are unclear to me, could you add some links for further reading or a brief description to the items? Several of my original questions are still unanswered, so I'll wait with marking your answer as correct. Thank you very much anyway @MCCCS! – mplattner – 2019-04-29T15:04:14.160
1@mplattner Thanks for the feedback. In a few days I’ll add a paragraph explanations to each. – MCCCS – 2019-04-29T16:47:05.553