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Re: [Cfrg] (flaws with Curve25519 DH function, if one does not check the output) Re: Elliptic Curves - curve form and coordinate systems

CodesInChaos <codesinchaos@gmail.com> Tue, 17 March 2015 09:52 UTC

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Date: Tue, 17 Mar 2015 10:52:54 +0100
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From: CodesInChaos <codesinchaos@gmail.com>
To: Watson Ladd <watsonbladd@gmail.com>
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Subject: Re: [Cfrg] (flaws with Curve25519 DH function, if one does not check the output) Re: Elliptic Curves - curve form and coordinate systems
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On Mon, Mar 16, 2015 at 4:39 PM, Watson Ladd <watsonbladd@gmail.com> wrote:
> Of
> course, we've always described what's required to ensure contributory
> behavior in Curve25519, and it's always the case that implementors
> should know what the protocol requires as far as assuring contributory
> behavior, namely rejecting 8 inputs.
What's a bit annoying is that the encoding of those inputs has changed
over time together with the interpretation of the MSB.

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