Time stamp incompatibility...may not be GnuPG's fault

Hideki Saito hideki at allcity.net
Tue Nov 7 01:04:24 CET 2000

This information actually came from Japanese GnuPG discussion.

Our finding shows that PGP is actually incrementing/decrementing 
timezone twice.

For example let's say that I signed the file at (with GnuPG):
Nov 06 20:06:40 2000 PST

Internally, it is recognized as Nov 07 04:06:40 2000 (GMT) which is 
973570000 seconds since 1970/1/1 00:00 GMT. 

:signature packet: algo 17, keyid 86E9B7C2A6E720DA
        version 3, created 973570000, md5len 5, sigclass 00
        digest algo 2, begin of digest a4 75
        data: [157 bits]
        data: [160 bits]

And if I decrypt this file using PGP in Japan (JST, +9 from GMT)
GnuPG would return as follows:
gpg: Signature made 11/07/00 13:06:40  using DSA key ID
while PGP would give:
Signed: 00/11/07 22:06:39

We found that the time PGP return is GMT Nov 07 04:06:40 2000 +9 
hours + 9 hours. This seems that it is doing the calculation twice.

This probably won't affect if both sides are using PGP. But this seems 
to be causing some incompatibility.

I sent this information also to PGP ML to get more information about 
this issue.

Hideki Saito mailto:hideki at allcity.net
PGP Fingerprint(0x82957B66): DE6B 1301 CC7F B915 521B  3736 4716 2919 8295 7B66

More information about the Gnupg-devel mailing list