{"type":"rich","version":"1.0","author_name":"npub1xauxlsk47g5nrj205uz9vp9l4s72s7z2dwlwenw2r573mjsnvxnqcslhw9","author_url":"https://nostr.ae/npub1xauxlsk47g5nrj205uz9vp9l4s72s7z2dwlwenw2r573mjsnvxnqcslhw9","provider_name":"njump","provider_url":"https://nostr.ae","html":"📅 Original date posted:2017-10-01\n📝 Original message:Just a simple suggestion since the signature format is changed. Can this be\ndesigned so that possible future hard forks can simply change 1 constant in\nthe code and turn on cross chain replay protection?\n\nOn Sun, Oct 1, 2017 at 1:05 PM Mark Friedenbach via bitcoin-dev \u003c\nbitcoin-dev at lists.linuxfoundation.org\u003e wrote:\n\n\u003e Clean stack should be eliminated for other possible future uses, the most\n\u003e obvious of which is recursive tail-call for general computation capability.\n\u003e I’m not arguing for that at this time, just arguing that we shouldn’t\n\u003e prematurely cut off an easy implementation of such should we want to. Clean\n\u003e stack must still exist as policy for future soft-fork safety, but being a\n\u003e consensus requirement was only to avoid witness malleability, which\n\u003e committing to the size of the witness also accomplishes.\n\u003e\n\u003e Committing to the number of witness elements is fully sufficient, and\n\u003e using the number of elements avoids problems of not knowing the actual size\n\u003e in bytes at the time of signing, e.g. because the witness contains a merkle\n\u003e proof generated by another party from an unbalanced tree, and unbalanced\n\u003e trees are expected to be common (so that elements can be placed higher in\n\u003e the tree in accordance with their higher expected probability of usage).\n\u003e Other future extensions might also have variable-length proofs.\n\u003e\n\u003e \u003e On Sep 30, 2017, at 7:47 PM, Luke Dashjr \u003cluke at dashjr.org\u003e wrote:\n\u003e \u003e\n\u003e \u003e Should it perhaps commit to the length of the serialised witness data\n\u003e instead\n\u003e \u003e or additionally? Now that signatures are no longer variable-length,\n\u003e that'd be\n\u003e \u003e possible...\n\u003e \u003e\n\u003e \u003e As far as tail-call needs are concerned, CLEANSTACK wouldn't have been\n\u003e checked\n\u003e \u003e until AFTER the tail-call in the first draft. But I suppose eliminating\n\u003e it for\n\u003e \u003e other possible future purposes is still useful.\n\u003e \u003e\n\u003e \u003e Luke\n\u003e\n\u003e _______________________________________________\n\u003e bitcoin-dev mailing list\n\u003e bitcoin-dev at lists.linuxfoundation.org\n\u003e https://lists.linuxfoundation.org/mailman/listinfo/bitcoin-dev\n\u003e\n-------------- next part --------------\nAn HTML attachment was scrubbed...\nURL: \u003chttp://lists.linuxfoundation.org/pipermail/bitcoin-dev/attachments/20171001/4e1497ee/attachment-0001.html\u003e"}