AS2Secure is a PHP Lib to allow you to send and receive AS2 message from partners. Based on OpenSSL, documents are SIGNED and CRYPTED to build SMIME messages ready to be sent over HTTP connection.
EXOS is a J2ME library for mobile devices to securely exchange data over the Internet with multiple groups of people, who are permitted to read different parts of the data only. EXOS takes care of authentication and key exchange (involves a server).