PGP and Security Utilities
- A collection of security utilities for RISC OS. Includes front ends for PGP, allowing PGP to be used for e-mail and files.
- http://www.queen.clara.net/pgp/acorn.html

PhotoSteg
- Will disguise any type of data within pre-drawn RISC OS 24- or 32-bit sprites.
- http://web.ukonline.co.uk/david.thomson/riscos/software.html

Enigma Simulator
- Fully functional, accurate simulator of the infamous German Enigma encryption machine invented in 1918.
- http://www.xat.nl/enigma/

GnuPG
- Port of GnuPG (Privacy Guard) by Steffan Bellon.
- http://www.sbellon.de/gnupg.html