A Beta test version of OTP-PC is ready for release. OTP-PC is a MS DOS version of the Vernam One-time pad, an unbreakable but somewhat clumsy cipher. I have added several features to make the one-time pad easier to use. -OTP-PC can use a large pad (codebook) for multiple messages. This feature is more efficient than using multiple smaller pads. -Optional Precompression of the plain text reduces consumption of the pad, and masks the size of the original file. -The portions of the pad used each session are overwritten, both on encoding and decoding, to prevent reuse. -Encoded files have a 2-stage header. The first stage, an un- encrypted "bootstrap", automates the decode process. The second encrypted header contains more sensitive information. -A 32 bit CRC (stored in the encrypted header) verifies reconstruction of the original file. -Automatic wiping of intermediate compressed files. If anyone would like to volunteer to test OTP-PC, and give me any suggestions or bug reports, please send me a message. Please indicate your preference for UUencode, Mime Base64, BinHex, or PGP ASCII Armor. I will send you both the executable and ANSI C (Borland C++ V3.0) source code. Jim Pinson jpinson@fcdarwin.org.ec