John:
I respectfully disagree with your statement: "This is completely parallel to
the public key certificate situation." The v1, v2 and v3 X.509 public key
certificate syntaxes defined in the 1997 and 2000 X.509 Recommendations are
compatible. The Attribute Certificate syntaxes defined in the 1997 and 2000
X.509 Recommendations are incompatible. The 2000 AC syntax can't be used to
decode a 1997 AC and vice versa.
I missed your point altogether. Now I get it.
I spoke with Hoyt about this issue at the RSA Conference. Someone is
looking into making them backward compatible. I am not sure how this will
be sorted out, but I will find out and report back.
Russ