Riordan's Internet Privacy Enhanced Mail (RIPEM) is a (not yet complete, but useful) implementation of Privacy Enhanced Mail (PEM). RIPEM allows your electronic mail to have the four security facilities provided by PEM: disclosure protection (optional), originator authenticity, message integrity measures, and non-repudiation of origin (always). RIPEM was written primarily by Mark Riordan <mrr@scss3.cl.msu.edu>. Most of the code is in the public domain, except for the RSA routines, which are a library called RSAREF licensed from RSA Data Security Inc. The current (November 1993) version of RIPEM is 1.1a; the current version of the Macintosh port of RIPEM is 0.8b1.