📅 Original date posted:2016-11-16
📝 Original message:No, BIP30 prevents duplicate tx hashes in the case where the new tx hash
duplicates that of a preceding tx with unspent outputs.
There was one such case that had already become buried in the chain at
the time, so it was exempted from validation. There was another case of
a duplicate hash, but it's predecessor was spent so it complied with the
new rule.
Both of these cases resulted from exact duplicate txs, which BIP34 now
precludes. However nothing precludes different txs from having the same
hash.
e
On 11/16/2016 04:06 PM, Jorge Timón wrote:
> On Thu, Nov 17, 2016 at 1:00 AM, Eric Voskuil <eric at voskuil.org> wrote:
>> This is a misinterpretation of BIP30. Duplicate transaction hashes can
>> and will happen and are perfectly valid in Bitcoin. BIP34 does not
>> prevent this.
>
> Sorry for moving the topic, but isn't duplication of tx hashes
> precisely what BIP30 prevents?
> That was my undesrtanding but should read it again.
> Since regular txs take inputs, the collision is extremely unlikely
> (again, this is my understanding, please correct me when wrong), the
> worrying case is coinbase txs (which don't have input to take entropy
> from). By introducing the committed height, collisions on coinbase txs
> are prevented too.
>
> If I'm wrong on any of this I'm more than happy to learn why.
>
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Eric Voskuil [ARCHIVE] /
npub1sg…ppx3c
2023-06-07 17:54:25
in reply to nevent1q…3je4
Author Public Key
npub1sgs97fe0n9wehe6zw7drcxdz4cy9yt9pfqjv8gasz5jlk4zezc0quppx3cSeen on
wss://relay.noswhere.comPublished at
2023-06-07 17:54:25Event JSON
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"content": "📅 Original date posted:2016-11-16\n📝 Original message:No, BIP30 prevents duplicate tx hashes in the case where the new tx hash\nduplicates that of a preceding tx with unspent outputs.\n\nThere was one such case that had already become buried in the chain at\nthe time, so it was exempted from validation. There was another case of\na duplicate hash, but it's predecessor was spent so it complied with the\nnew rule.\n\nBoth of these cases resulted from exact duplicate txs, which BIP34 now\nprecludes. However nothing precludes different txs from having the same\nhash.\n\ne\n\nOn 11/16/2016 04:06 PM, Jorge Timón wrote:\n\u003e On Thu, Nov 17, 2016 at 1:00 AM, Eric Voskuil \u003ceric at voskuil.org\u003e wrote:\n\u003e\u003e This is a misinterpretation of BIP30. Duplicate transaction hashes can\n\u003e\u003e and will happen and are perfectly valid in Bitcoin. BIP34 does not\n\u003e\u003e prevent this.\n\u003e \n\u003e Sorry for moving the topic, but isn't duplication of tx hashes\n\u003e precisely what BIP30 prevents?\n\u003e That was my undesrtanding but should read it again.\n\u003e Since regular txs take inputs, the collision is extremely unlikely\n\u003e (again, this is my understanding, please correct me when wrong), the\n\u003e worrying case is coinbase txs (which don't have input to take entropy\n\u003e from). By introducing the committed height, collisions on coinbase txs\n\u003e are prevented too.\n\u003e \n\u003e If I'm wrong on any of this I'm more than happy to learn why.\n\u003e \n\n-------------- next part --------------\nA non-text attachment was scrubbed...\nName: signature.asc\nType: application/pgp-signature\nSize: 490 bytes\nDesc: OpenPGP digital signature\nURL: \u003chttp://lists.linuxfoundation.org/pipermail/bitcoin-dev/attachments/20161116/417a75b2/attachment.sig\u003e",
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