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From: Thomas Voegtlin <thomasv1@gmx.de>
To: bitcoin-development@lists.sourceforge.net
Subject: Re: [Bitcoin-development] Proposal to replace BIP0039
Date: Sat, 02 Nov 2013 10:44:58 +0100	[thread overview]
Message-ID: <5274C99A.8060304@gmx.de> (raw)
In-Reply-To: <CAJna-Hj+q7oyTj8SWiVESPt5Web-mLuDhv7yA8zF5wRD81aBXA@mail.gmail.com>


> To be specific, we (in cooperation with / inspired by Timo Hanke) 
> developed method how to prove that the seed generated by Trezor has 
> been created using combination of computer-provided entropy and 
> device-provided entropy, without leaking full private information to 
> other computer, just because we want Trezor to be blackbox-testable 
> and fully deterministic (seed generation is currently the only 
> operation which uses any source of RNG).
>

Thanks for the explanation. Here is how I understand how it works, 
please correct me if I'm wrong:

The user's computer picks a random number a, the Trezor picks a random 
number b.
Trezor adds a and b in the secp256k1 group, and this creates a master 
private key k.
Trezor sends the corresponding master public key K to the computer.
Thus, the computer can check that K was derived from a, without knowing b.
This also allows the computer to check that any bitcoin address derived 
from K is derived from a, without leaking b. (and reciprocally)

However, it seems to me that this property will work only with bip32 
public derivations; if a private derivation is used, don't you need to 
know k?




  parent reply	other threads:[~2013-11-02  9:45 UTC|newest]

Thread overview: 24+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2013-10-24 17:29 [Bitcoin-development] Proposal to replace BIP0039 thomasV1
2013-10-24 18:09 ` slush
2013-10-25  9:27   ` Thomas Voegtlin
2013-10-24 18:54 ` slush
2013-10-26 15:24   ` Thomas Voegtlin
2013-10-26 20:47     ` slush
2013-10-26 21:30       ` Pieter Wuille
2013-10-31  9:13         ` Thomas Voegtlin
2013-10-31 10:41           ` slush
2013-10-31 11:07             ` Peter Todd
2013-11-02  9:44             ` Thomas Voegtlin [this message]
2013-11-03  6:41               ` Timo Hanke
2013-11-03  7:03                 ` Thomas Voegtlin
2013-11-03  7:40                   ` Timo Hanke
2013-11-03  8:39                     ` Thomas Voegtlin
2013-11-04 15:10                       ` Timo Hanke
2013-11-16 23:41                         ` Pavol Rusnak
2013-11-16 23:49                     ` Pavol Rusnak
2013-11-17  0:42                       ` Timo Hanke
2013-11-17  0:49                         ` Pavol Rusnak
2013-10-31 11:11           ` slush
2013-10-31 11:18             ` slush
2013-11-02 10:10               ` Thomas Voegtlin
2013-10-24 21:55 ` Luke-Jr

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