From: Gregory Maxwell <gmaxwell@gmail•com>
To: Eric Lombrozo <elombrozo@gmail•com>
Cc: Bitcoin Development <bitcoin-development@lists•sourceforge.net>
Subject: Re: [Bitcoin-development] New side channel attack that can recover Bitcoin keys
Date: Wed, 5 Mar 2014 13:44:30 -0800 [thread overview]
Message-ID: <CAAS2fgTGDzPFDP=ii08VXcXYpWr2akYWxqJCNHW-ABuN=ESc8A@mail.gmail.com> (raw)
In-Reply-To: <0720C223-E9DD-4E76-AD6F-0308CA5B5289@gmail.com>
On Wed, Mar 5, 2014 at 1:31 PM, Eric Lombrozo <elombrozo@gmail•com> wrote:
> If we don't mind sacrificing some performance when signing, there's a fairly
> simple way to implement a constant-time constant-cache-access-pattern
> secp256k1.
> It is based on the idea of branchless implementations of the field and group
> operations.
Do take care that branchless doesn't mean side-channel free: On
non-trivial hardware you must have uniform memory accesses too.
(and that itself isn't enough for sidechannel freeness against an
attacker that can do power analysis... then you star worrying about
the internal structure your primitive adders and the hamming weight of
your numbers, and needing to build hardware that uses differential
logic, and yuck yuck yuck: This is why you still shouldn't reuse
addresses, and why a blinding approach may still be sensible, even if
you believe your implementation is hardened against side-channels)
next prev parent reply other threads:[~2014-03-05 21:44 UTC|newest]
Thread overview: 24+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-03-05 12:49 Mike Hearn
2014-03-05 12:56 ` Pieter Wuille
2014-03-05 13:18 ` Jean-Paul Kogelman
2014-03-05 14:04 ` Pieter Wuille
2014-03-05 16:21 ` Kevin
2014-03-05 19:39 ` Peter Todd
2014-03-05 19:51 ` Gregory Maxwell
2014-03-05 20:32 ` Peter Todd
2014-03-05 20:54 ` Gregory Maxwell
2014-03-12 9:44 ` Peter Todd
2014-03-05 22:17 ` James Hartig
2014-03-05 22:26 ` Eric Lombrozo
2014-03-06 7:02 ` Odinn Cyberguerrilla
2014-03-08 19:34 ` Luke-Jr
2014-03-09 1:57 ` Gregory Maxwell
2014-03-05 21:31 ` Eric Lombrozo
2014-03-05 21:44 ` Gregory Maxwell [this message]
2014-03-05 22:14 ` Eric Lombrozo
2014-03-05 22:25 ` Gregory Maxwell
2014-03-06 8:38 ` Mike Hearn
2014-03-06 10:00 ` Natanael
2014-03-25 13:39 ` Troy Benjegerdes
2014-03-25 13:50 ` Gavin Andresen
2014-03-08 19:29 ` Gustav Simonsson
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