Email encryption software

One of the most common uses of encryption is encrypting emails. Sending sensitive messages, documents and files over the Internet is like sending a postcard as all emails are transmitted in an unsecured form. It doesn’t depend on if you send emails via public and private networks. Your message is totally open to interception by anyone along the way – so anybody – your ISP, your boss, etc. can read your emails. Even if you connect to your server and send your emails via SSL, it only means that your emails can’t be seen while transmitting between you and your server. When your email reaches your server, it can be seen by your email service provider. Then your server usually sends your email to the recipient in an unsecured way and your email can also be easily seen by anyone.
Private network, where email goes directly to a mail server and resides there until it is retrieved, also doesn’t provide necessary security level, as you email can be seen e.g. by network administrator, your boss, etc.Of course, you may believe that your personal email does not contain any private information, but everyone has got something to keep in secret from his family, neighbors or colleagues. It could be financial, social, or professional secrets. There is really only one sure way to protect your email privacy – email encryption.E-mail encryption can rely on public-key encryption system. Public-key encryption uses different keys for encryption and decryption. The encryption key is public so that anyone can encrypt a message. However, the decryption key is private, so that only the receiver is able to decrypt the message. It is common to set up ‘key-pairs’ within a network so that each user has a public and private key. The public key is made available to everyone so that they can send messages, but the private key is only made available to the person it belongs to.

The sender and the recipient must have the same software. The recipient makes a pair of keys – public key and private key (both keys can be unlocked with a single password). Public key can be used by anyone with the same software to encrypt a message. Public keys can be freely distributed without worrying since it is only used to scramble (encrypt) the data.The sender does not need the recipient’s password to use his or her public key to encrypt data. The recipient’s other key is a private key that only he or she can use when decrypting the message. Private key should never be distributed since the private key assures that only the intended recipient can unscramble (decrypt) data intended for him or her. The recipient can freely distribute the public key without worrying since it is only used to scramble the data.

PGP (Pretty Good Privacy) – is a public-private key cryptography system which allows users to more easily integrate the use of encryption in their daily tasks, such as electronic mail protection and authentication, and protecting files stored on a computer. PGP is available for free to individual home users. It was originally designed by Phil Zimmerman. It uses IDEA, CAST or Triple DES for actual data encryption and RSA (with up to 2048-bit key) or DH/DSS (with 1024-bit signature key and 4096-bit encryption key) for key management and digital signatures. The RSA or DH public key is used to encrypt the IDEA secret key as part of the message.