Two different cryptographic methods, private-key and public-key encryptions, solve computer security problems. Private-key encryption is also known as symmetric encryption. In private-key encryption, the sender and receiver of information share a key that is used for both encryption and decryption. In public-key encryption, two different mathematically related keys, known as a key pair, are used to encrypt and decrypt data. Information encrypted using one key can only be decrypted by using the other member of the key pair. BIRT’s default encryption plug-in supports the following algorithms within these two methods:
Triple-DES or DESede is an improvement over DES. This algorithm uses three DES keys k1, k2, and k3. A message is encrypted using k1 first, then decrypted using k2 and encrypted again using k3. This technique is called DESencryptiondecryptionencryption. Two or three keys can be used in DESede. This algorithm increases security as the key length effectively increases from 56 to 112 or 168.