Re: 128bit RSA public key - time to break?

From: Robert Harley (harley@jaune.inria.fr)
Date: 02/24/03 

From: Robert Harley <harley@jaune.inria.fr>
Date: 24 Feb 2003 18:51:00 +0100

shanehird@hotmail.com (shane) writes:
> I realise that a 128bit key would be exceptionally weak, but I haven't
> been able to find out just how weak it is.
>
> I am in need of a small public key, which would provide security from
> a typical user for about 6 months. [...]
> [...] I considered ECC, but it seems to have a minimum of
> 160bits. Is this the case?

ECC will give you the best strength-per-bit of any public-key method.
A reasonable estimate is that 128-bit ECC would take 1 million years
to break on one PC, which fits your constraints. On the other hand,
128-bit RSA would take about 0.1 seconds to break.

Regards,
  Rob.
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