I’ve received two files from the same sender who uses OpenPGPBlackbox, they assure me that they are both encrypted the same way with the same parameters, just at different times. The sender is located in Sydney, NSW, Australia and I am
located in Auckland, New Zealand. The files are generated at 10pm and 4am Sydney time. Both of the files decrypt correctly using GnuPG 2.1.18 but the one generated at 10pm receives bad signature, while the one at 4am receives good signature irrelevant of
what time I try to decrypt them. The times of the signing that GPG reports are correct (in American date format).
My question is whether there is anything else I can do to troubleshoot this issue to get to the bottom of the problem ?