I tried to contact the Crypt::RIPEMD160 author today, as well as a bunch of people listed in the README, etc. 5 of the 8 emails bounced immediately. There's a 64bit bug in the module that is causing issues with Crypt::OpenPGP.
Their name is Christian H. Geuer-Pollmann or CHGEUER in pause. If anyone knows how to contact them, I'd like to help fix some of the bugs in this module