Erik Leunissen kirjoitti: > When computing DSA signatures, the first eight bytes of the signature > appear to follow a rather predictable pattern, which I am concerned about. > > I've tested this to be so using two slightly different input texts: > 1. "Mary had a little lamb" > 2. "Mary had a little lama" > > For each of these two texts, I computed 10 signatures (all from the same > signing key). The signatures (if expressed in hexadecimal format) all > start with an 8 byte sequence that matches the regular expression: > > 302[cde]021[45] > > > Because DSA signatures are computed from SHA1 hashes, I also computed > these SHA! hashes for each of the two inputs. I was relieved to see that > the hashes were very different. > > Therefore, the observed pattern must come from whatever DSA_sign() does > after the hash has been computed. > > (The test script and its output for one run over > the two texts are appended to this message) > > > Is the observed pattern normal? > > > Thanks in advance for any advice, > > Erik Leunissen. >
It's a magic/header that tells the recipient that this is indeed DSA signature. Aki Tuomi
signature.asc
Description: OpenPGP digital signature
