Will DSS keys still be preferred over RSA in a few months?

L. Sassaman rabbi@quickie.net
Mon, 10 Jul 2000 10:04:08 -0700 (PDT)


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On Sun, 9 Jul 2000, [iso-8859-1] Ulf Möller wrote:


> On Sun, Jul 09, 2000 at 11:36:43AM -0400, Ulf Möller wrote:
>
> > but is unauthenticated. That means that it is sufficient to find a
> > collision in any one of the supported OpenPGP hash functions
> > (which include MD5 and MD2) to forge a DSA signature.
>
> That's not exactly accurate. Anyway, on the bottom line, OpenPGP RSA
> allows the signer to choose the (best) hash algorithm, and OpenPGP DSA
> allows the attacker to choose the (worst) hash algorithm.
Please explain this further. First of all, there is no difference between "RSA" and "DSA" key usage in OpenPGP. I think that what you mean to compare here is "v3" and "v4" keys. Is that correct? Secondly, there is a self-signature preference for hash algorithms. It would be very easy for an implementation to declare a signature "BAD" if a hash was used that was not expressly permitted in the signing key's self-signature pref for hashes. This, I think, is a worthwhile thing to suggest to the working group. __ L. Sassaman System Administrator | Technology Consultant | "Credo quia absurdum." icq.. 10735603 | pgp.. finger://ns.quickie.net/rabbi | --Tertullian -----BEGIN PGP SIGNATURE----- Comment: OpenPGP Encrypted Email Preferred. iD8DBQE5agIRPYrxsgmsCmoRArEOAKCroyCh02vlE9j/3qdtAKsn46awewCgiSpM v+qozpxx2kRKNSI/DEvGQIc= =Gt2H -----END PGP SIGNATURE-----