This is a 2048 Bit RSA Crypto System which requires a java runtime environment on your machine. RSA 2048 bit crytographic software download. Used for limited ammount of Text, as the keys are quazi keys - often not real and will not do for bulk encryption. It uses Java's BigInteger class which is efficient at generating large primes, and the algorithms are extremely fast, allowing good response times.
The trade off is that the generated Primes are not tested fully to ensure they can act as keys: with this in mind, you will have to generate keys, and try to encrypt and decrypt the same text to ensure that the plain text is retreived again before storing a key. SMTP (Simple mail transfer protocal enabled) allowing users to send encrypted mail via TCP/IP stack live wire; also allows you to encrypt then test the encryption by decrypting the text, and storing the key to persistent storage.