The encryption of emails is becoming more and more popular, and there are plenty of programs out there that do it. Puffer was one of the first to bring encryption to the hands of the public at an affordable price.

Puffer uses public key cryptography, which involves the use of two keys: a public key to encrypt data and a private key to decrypt data. You supply your public key to all those who may want to send email to you and, on receiving an encrypted email from them, you decrypt it using your private key (aka your public key password).

You create both keys by entering a password into Puffer and then randomly hitting the keyboard, creating two mathematically related keys. At this point you select your desired level of encryption from 512bit to 1536bit.

Puffer can be used to encrypt any file you wish, not just text, and works in conjunction with your email client. You can write and encrypt message in Puffer, and automatically send them using your default email client.