Strange crypto choices

Yegor Ievlev koops1997 at
Tue May 29 00:23:29 AEST 2018

A backdoored curve could be easily generated using the algorithm used
to generate the NIST curves.

The algorithm that generates a backdoored curve is very simple:
Suppose the NSA (the author of the curves) knows a way to solve ECDLP
in polynominal time for some rare (one in 2^32) curves. In this case,
they simply keep generating the curves until they will find one that
is weak to their algorithm for solving ECDLP. The computations
required only take two days on a cluster of 41 GTX 780 GPUs, and was
feasible to do with a cluster of specialized hardware in 1999, when
the curves were generated.

Neither RSA nor Curve25519 are vulnerable to similar attacks.

On Mon, May 28, 2018 at 1:36 AM, Damien Miller <djm at> wrote:
> On Mon, 28 May 2018, Yegor Ievlev wrote:
>> Can we prefer RSA to ECDSA? For example:
>> HostKeyAlgorithms
>> ssh-rsa,ssh-ed25519,ecdsa-sha2-nistp521,ecdsa-sha2-nistp384,ecdsa-sha2-nistp256
> not without a good reason

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