Ciphire Mail works with your existing e-mail program, allowing you to encrypt and decrypt your messages, and digitally sign them to prove that they came from you.

The client software sits on your computer and through a simple interface allows you to make sure that any communications you want to keep private, stay private.

It is compatible with any e-mail client that uses POP, IMAP and SMTP protocols - this covers almost all ISP e-mail accounts, but it will not cover webmail offerings such as Hotmail or Gmail.

It works on a known technology called public key cryptography to ensure that your communications, once encrypted, can only be seen by their intended recipient. You can also digitally "sign" a message so, while it won't be encrypted, the signature will prove that it is from you.

Both parties will need to have Ciphire Mail installed, however.