On Tue, Dec 27, 2005 at 09:38:05AM -0800, "Hal Finney" wrote:
I'd suggest that clearsigning is aimed more at applications which will
present the signed document to users as it was received "on the wire",
so that they can read it usefully even with the signature in place.
For that purpose the important thing is to know exactly how the signature
will be verified so that signers can create valid documents. I think
we agree that the spec is adequate for this purpose.
For data interchange, you want to start with a document on one machine
and sign or encrypt it, send it to another machine and verify/decrypt,
getting back the same document. For that purpose the binary formats
work well.
The problem arises if you want to clearsign but still get data
interchange. The sender needs to know not only how the data will get
verified, but also how it will be stored if the signature is stripped
away. We didn't spec this because it didn't seem to fit that well into
the clearsign model, which is oriented around presenting data with the
signatures in place.
I think the concern is not so much that we need the ability to data
interchange, but that there is a point of ambiguity in the standard
such that
Un-Clearsign ( Clearsign ( A ) ) != A
in some cases, specifically around the lack or presence of a line
ending on the final line of A.
David