One benefit of using CFB is that you don't need to pad your plaintext.
As for why it was chosen... I think that answer is probably lost in
the mystery of time (read: it was like that in PGP 2.0 and nobody had
a good reason to change it).
-derek
john(_dot_)dlugosz(_at_)kodak(_dot_)com writes:
Why does OpenPGP use a custom CFB mode instead of CBC mode? CFB with the
slide equal to the blocksize is basically different from CBC in that the
encryption is done before combining, rather than after.
I presume its simply always been that way, and it's not a problem so it was
never changed in an update. But why was that chosen initially, if anybody
knows, and are there any propblems with CBC that this avoids?
--John
--
Derek Atkins
Computer and Internet Security Consultant
derek(_at_)ihtfp(_dot_)com www.ihtfp.com