Electronic Identity The natural way to enable users of all levels to encrypt their messages. This is the primary source of information with the most up-to-date papers (mostly in German language): http://encryption-4-all.gilbertbrands.de/ International stuff will one fine day be available here: Polymorphic Encryption The Giant Block Size Polymorphic Symmetric Cipher is described here: giant_block_size_polymorphic_cipher.pdf C++ source code which demonstrates the basic functionality is available online here: