Re: [TLS] What would make TLS cryptographically better for TLS 1.3

Robert Ransom <rransom.8774@gmail.com> Fri, 01 November 2013 21:34 UTC

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Date: Fri, 1 Nov 2013 14:34:48 -0700
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From: Robert Ransom <rransom.8774@gmail.com>
To: Nico Williams <nico@cryptonector.com>
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Subject: Re: [TLS] What would make TLS cryptographically better for TLS 1.3
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On 10/31/13, Nico Williams <nico@cryptonector.com> wrote:

>  - Many fewer nonce bytes and random IVs where possible.  Nonce payloads
>    should be sent when needed, if needed.  For example, to derive a
>    session key from an DHE shared secret one does not really need
>    nonces.  This means that counter modes are better, for example, than
>    CBC modes.

If the server sends a nonce during a DHE/ECDHE key exchange, the
server can safely reuse its DH keypair for multiple clients with no
further design or implementation considerations.  If the server does
not send a nonce, it must keep a replay-detection cache of client DH
public keys for the lifetime of its DH keypair.


Robert Ransom