UFONet - Denial of Service Toolkit
FinalCrypt - Unbreakable One-Time Pad Encryption
JavaCard/smart card implementation of the ISO7816 and PKI standard
Base64 encode (or decode) files of any type with this lightweight tool
Enigma Encryption Simulator in Java
PGP graphical user interface
minimalistic, secure and autonomous P2P messenger
IPsec / IKEv2-based VPN software for Linux.
The best cryptography playground available