[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
Re: Generating 3DES keys from SKEYID_e
Paul Koning wrote:
>
> >>>>> "Glawitsch," == Glawitsch, Gregor <Gregor_Glawitsch@nai.com> writes:
>
> Glawitsch,> Stephane, do you realize how large 2^128 is?
>
> While it doesn't matter for 3DES (since the effective key strength is
> less than 2^128) this issue will matter for AES.
>
> Yes, 2^128 is a big number. But if you want to claim support for
> ciphers with long keys, by his argument you need a PRF of
> corresponding size. There's something to be said for that.
>
> The alternative, of course, is not to support keys larger than 128
> bits. That's in practice not a bad idea.
>
> paul
Another alternative would be to use Tiger as the hash. That is a
SHOULD in RFC 2409 and gives a 192-bit hash.
http://www.cs.technion.ac.il/~biham/Reports/Tiger/
Follow-Ups:
References: