From: Adam Back <adam@cypherspace•org>
To: Peter Todd <pete@petertodd•org>
Cc: Bitcoin Dev <bitcoin-development@lists•sourceforge.net>
Subject: Re: [Bitcoin-development] The relationship between Proof-of-Publication and Anti-Replay Oracles
Date: Sun, 21 Dec 2014 10:01:37 +0000 [thread overview]
Message-ID: <CALqxMTHC0Rhotei4B1civoc_9NF5M+tw-qmE46EmHSadCrmScQ@mail.gmail.com> (raw)
In-Reply-To: <20141220144800.GA26284@savin.petertodd.org>
On 20 December 2014 at 14:48, Peter Todd <pete@petertodd•org> wrote:
> We need the following primitives operating on message m, pubkey p, and a
> valid signature sig1 for m, p:
>
> AntiReplaySign(m, p, sig1) -> sig2
> VerifyAntiReplaySig(m, p, sig2) -> True or False
>
> Additionally once AntiReplaySign() has been used once for a given pubkey
> it is impossible to re-run the primitive on a different message m'. This
> is of course impossible to implement with math alone, but we can
> implement it with a trusted third party.
Well while you cant prevent it you could render it insecure enabling
miners to take funds.
That could work via a one-show signature; normal ECDSA being address
a=H(Q), public key Q=dG, R=kG, r=R.x, s=(H(m)+rd)/k, signature (r,s),
verify: a=?H(Q) and sR=?H(m)G+rQ one-show being: a=H(Q,R), verify
being: a=?H(Q,R) and sR=?H(m)G+rQ. Now that is unsafe to double-spend
by design as only that specific R is usable and as we know reusing R
with different messages leaks the private key because: s=(H(m)+rd)/k
and s'=(H(m')+rd)/k implies sk=H(m)+rd and s'k=H(m')+rd so
k=(H(m)-H(m'))/(s'-s), and d=(sk-H(m))/r.
Adam
next prev parent reply other threads:[~2014-12-21 10:01 UTC|newest]
Thread overview: 28+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-12-12 9:05 [Bitcoin-development] Setting the record straight on Proof-of-Publication Peter Todd
2014-12-12 12:25 ` Gareth Williams
2014-12-12 17:04 ` Alex Mizrahi
[not found] ` <CAOG=w-v3qjG3zd_WhfFU-OGnsHZEuYvY82eL4GqcdgY6np5bvA@mail.gmail.com>
2014-12-12 17:50 ` Alex Mizrahi
2014-12-13 13:32 ` Gareth Williams
2014-12-15 4:52 ` Peter Todd
2014-12-17 11:55 ` Gareth Williams
2014-12-21 6:12 ` Peter Todd
2014-12-15 4:17 ` Peter Todd
2014-12-12 13:41 ` odinn
2014-12-12 14:17 ` Justus Ranvier
2014-12-15 4:59 ` Peter Todd
2014-12-17 1:16 ` odinn
2014-12-20 14:48 ` [Bitcoin-development] The relationship between Proof-of-Publication and Anti-Replay Oracles Peter Todd
[not found] ` <CAOG=w-vrHPY1aCNndmoW9QyCh9XnWyv8uZn2PyjZ6rNg2MoSSw@mail.gmail.com>
2014-12-21 5:52 ` Peter Todd
[not found] ` <CAOG=w-tZke--6OsqNjJhE9SOdCwdZYZM8iz1VBTFziegt9UZWw@mail.gmail.com>
2014-12-21 7:01 ` Peter Todd
[not found] ` <CAOG=w-s1_VXJAKxBpMOK=B50qnHjxSe4J=vwwSfFPRz0_Cb9rA@mail.gmail.com>
2014-12-21 15:32 ` Peter Todd
2014-12-21 11:25 ` Jorge Timón
2014-12-21 16:07 ` Peter Todd
2014-12-21 19:39 ` Jorge Timón
2014-12-21 10:01 ` Adam Back [this message]
2014-12-21 15:29 ` Peter Todd
2014-12-21 13:49 ` paul snow
2014-12-21 15:22 ` Peter Todd
2014-12-21 15:41 ` paul snow
2014-12-22 0:11 ` Peter Todd
2015-01-06 11:03 ` joliver
2014-12-22 20:05 ` Adam Back
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