From: Jonas Nick <jonasdnick@gmail•com>
To: moonsettler <moonsettler@protonmail•com>,
Bitcoin Protocol Discussion
<bitcoin-dev@lists•linuxfoundation.org>
Subject: Re: [bitcoin-dev] Blinded 2-party Musig2
Date: Wed, 26 Jul 2023 14:59:42 +0000 [thread overview]
Message-ID: <d1db8481-140b-a0b4-8c24-4486f8a1cab6@gmail.com> (raw)
In-Reply-To: <O3LTbUbjNa3SLUfJzSKDNLBCIhED_6rdOcmgLpYB9byX6HBVg3BMu3hrvY37fH4SGL8th8oJaVV6_ogl_ZOA0qTXgENq8xqQNSRB-VsHem4=@protonmail.com>
While this may solve blinding, I don't see how it solves the problem that the
client can forge signatures because the client is in control of challenge e'.
This is not special to MuSig(2), but is also the reason why original blind
Schnorr signatures are insecure (as demonstrated in David Wagner's "A
Generalized Birthday Problem" paper).
For some more recent work on blind Schnorr signatures, see:
- https://eprint.iacr.org/2019/877.pdf Blind Schnorr Signatures and Signed
ElGamal Encryption in the Algebraic Group Mode
- https://eprint.iacr.org/2020/1071.pdf On Pairing-Free Blind Signature Schemes
in the Algebraic Group Model
In particular, the first paper proposes a less-efficient variant of blind
Schnorr signatures that is secure under concurrent signing if the "mROS" problem
is hard (which is imho plausible). Another potential approach is using
commitments and a ZKP as I mentioned earlier in this thread. This scheme is
"folklore", in the sense that it is being discussed from time to time but isn't
specified and does not have a security proof as far as I am aware.
next prev parent reply other threads:[~2023-07-26 14:59 UTC|newest]
Thread overview: 34+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-07-24 7:46 Tom Trevethan
2023-07-24 10:50 ` ZmnSCPxj
2023-07-24 14:25 ` Erik Aronesty
2023-07-24 16:08 ` Tom Trevethan
2023-07-24 15:57 ` Tom Trevethan
2023-07-24 14:12 ` Jonas Nick
2023-07-24 14:40 ` Erik Aronesty
2023-07-24 15:40 ` Jonas Nick
2023-07-24 16:51 ` AdamISZ
2023-07-25 14:12 ` Erik Aronesty
2023-07-25 16:05 ` Tom Trevethan
2023-07-26 4:09 ` Erik Aronesty
2023-07-26 17:40 ` Andrew Poelstra
2023-07-26 19:59 ` Jonas Nick
2023-07-26 20:35 ` Tom Trevethan
2023-07-26 22:06 ` Erik Aronesty
2023-07-27 2:54 ` Lloyd Fournier
2023-07-27 8:07 ` Jonas Nick
[not found] ` <CAJvkSsfa8rzbwXiatZBpwQ6d4d94yLQifK8gyq3k-rq_1SH4OQ@mail.gmail.com>
2023-07-27 13:25 ` [bitcoin-dev] Fwd: " Tom Trevethan
2023-08-07 0:55 ` [bitcoin-dev] " Tom Trevethan
2023-08-08 17:44 ` moonsettler
2023-08-09 15:14 ` Tom Trevethan
2023-08-10 3:30 ` Lloyd Fournier
2023-08-10 11:59 ` Tom Trevethan
2023-08-14 6:31 ` Lloyd Fournier
2023-08-30 10:52 ` Tom Trevethan
2023-07-24 15:39 ` Jonas Nick
2023-07-24 16:22 ` Tom Trevethan
2023-07-26 9:44 ` moonsettler
2023-07-26 14:59 ` Jonas Nick [this message]
2023-07-26 19:19 ` AdamISZ
2023-07-26 19:28 ` moonsettler
2023-07-27 5:51 ` AdamISZ
[not found] <mailman.125690.1690381971.956.bitcoin-dev@lists.linuxfoundation.org>
2023-07-26 16:32 ` Tom Trevethan
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