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Re: ElGamal, EME-PKCS1-v1_5

"Daniel A. Nagy" <nagydani@epointsystem.org> Thu, 24 June 2010 21:17 UTC

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Message-ID: <4C23CB67.3000703@epointsystem.org>
Date: Thu, 24 Jun 2010 23:17:27 +0200
From: "Daniel A. Nagy" <nagydani@epointsystem.org>
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To: Brian Lewis <brian@monetra.com>
CC: ietf-openpgp@imc.org
Subject: Re: ElGamal, EME-PKCS1-v1_5
References: <20100624173119.GJ25604@brian.internal.monetra.com>
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Hello,

Brian Lewis wrote:
> So I need m = EME-PKCS1-v1_5(...). According to
> http://tools.ietf.org/html/rfc3447#section-7.2.1, PS is k - mLen
> - 3 random nonzero bytes, where k is the length of RSA n in bytes. But I
> don't have RSA n. I have ElGamal p, g, and y.
> 
> In EME-PKCS1-v1_5, what is k if I'm using ElGamal?

You should use the length of ElGamal p.

-- 
Daniel

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