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Re: [Cfrg] Elliptic Curves - signature scheme: friendliness to low memory implementations (ends on June 3rd)

Tony Arcieri <bascule@gmail.com> Thu, 21 May 2015 00:28 UTC

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From: Tony Arcieri <bascule@gmail.com>
Date: Wed, 20 May 2015 17:27:42 -0700
Message-ID: <CAHOTMVL7eT+jU-jQv-y2OQNYevwux7BoCsPKz_GyZ34hnKKPug@mail.gmail.com>
To: Alexey Melnikov <alexey.melnikov@isode.com>
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Subject: Re: [Cfrg] Elliptic Curves - signature scheme: friendliness to low memory implementations (ends on June 3rd)
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On Wed, May 20, 2015 at 2:16 PM, Alexey Melnikov <alexey.melnikov@isode.com>
wrote:

> #3: option #2, but with an additional "large message" mode defined for
> protocols that feel that they need it, where the message to be signed is
> actually a hash of the true message.


Unless there's a specific reason why hashing 3 times in the "large message"
mode is "too slow", this seems like the best option to me. It provides a
defense against collisions and aside from the overhead of triple-hashing
should perform similarly in the "large message" case as the bottleneck for
large messages should be computing the digest over the large message, not
hashing hashes.

-- 
Tony Arcieri

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