📅 Original date posted:2018-02-15
📝 Original message:Den 15 feb. 2018 22:58 skrev "Tim Ruffing via bitcoin-dev" <
bitcoin-dev at lists.linuxfoundation.org>:
Also, the miners will indeed see one valid decommitment. This
decommitment may have been sent by the attacker but it's the preimage
chal of the address, because otherwise it's not valid for the malicious
commitment. But if the decommitment is chal, then this decommitment is
also valid for the commitment of the honest user, which is earliest
additionally. So the honest commitment wins. The attacker does not
succeed and everything is fine.
The reason why this works:
There is only one unique decommitment for the UTXO (assuming H_addr is
collision-resistant). The decommitment does not depend on the
commitment. The attacker cannot send a different decommitment, just
because there is none.
If your argument is that we publish the full transaction minus the public
key and signatures, just committing to it, and then revealing that later
(which means an attacker can't modify the transaction in advance in a way
that produces a valid transaction);
Allowing expiration retains insecurity, while allowing expiration makes it
a trivial DoS target.
Anybody can flood the miners with invalid transaction commitments. No miner
can ever prune invalid commitments until a valid transaction is finalized
which conflicts with the invalid commitments. You can't even rate limit it
safely.
Like I said in the other thread, this is unreasonable. It's much more
practical with simple hash commitment that you can "fold away" in a Merkle
tree hash and which you don't need to validate until the full transaction
is published.
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Natanael [ARCHIVE] /
npub179…lpmjt
2023-06-07 18:10:39
in reply to nevent1q…gtme
Author Public Key
npub1798ncudyucap9jzzujjsgufx8tdykm8auzfledjcs6f6wf4ekqvq8lpmjtPublished at
2023-06-07 18:10:39Event JSON
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"created_at": 1686161439,
"kind": 1,
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"content": "📅 Original date posted:2018-02-15\n📝 Original message:Den 15 feb. 2018 22:58 skrev \"Tim Ruffing via bitcoin-dev\" \u003c\nbitcoin-dev at lists.linuxfoundation.org\u003e:\n\n\nAlso, the miners will indeed see one valid decommitment. This\ndecommitment may have been sent by the attacker but it's the preimage\nchal of the address, because otherwise it's not valid for the malicious\ncommitment. But if the decommitment is chal, then this decommitment is\nalso valid for the commitment of the honest user, which is earliest\nadditionally. So the honest commitment wins. The attacker does not\nsucceed and everything is fine.\n\nThe reason why this works:\nThere is only one unique decommitment for the UTXO (assuming H_addr is\ncollision-resistant). The decommitment does not depend on the\ncommitment. The attacker cannot send a different decommitment, just\nbecause there is none.\n\n\nIf your argument is that we publish the full transaction minus the public\nkey and signatures, just committing to it, and then revealing that later\n(which means an attacker can't modify the transaction in advance in a way\nthat produces a valid transaction);\n\nAllowing expiration retains insecurity, while allowing expiration makes it\na trivial DoS target.\n\nAnybody can flood the miners with invalid transaction commitments. No miner\ncan ever prune invalid commitments until a valid transaction is finalized\nwhich conflicts with the invalid commitments. You can't even rate limit it\nsafely.\n\nLike I said in the other thread, this is unreasonable. It's much more\npractical with simple hash commitment that you can \"fold away\" in a Merkle\ntree hash and which you don't need to validate until the full transaction\nis published.\n-------------- next part --------------\nAn HTML attachment was scrubbed...\nURL: \u003chttp://lists.linuxfoundation.org/pipermail/bitcoin-dev/attachments/20180215/c5df0634/attachment-0001.html\u003e",
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}