Oracle PL/SQL for DBAs

Encryption Algorithms

There are many widely used and commercially available encryption algorithms, but we’ll focus here on the symmetric key algorithms supported by Oracle for use in PL/SQL applications. The DES and Triple DES algorithms are supported by both of Oracle’s built-in encryption packages: DBMS_CRYPTO and DBMS_OBFUSCATION_TOOLKIT; only DBMS_CRYPTO, introduced in Oracle Database 10g Release 1, supports AES, however.

Data Encryption Standard (DES)

Historically, DES has been the predominant standard used for encryption . It was developed more than 20 years ago for the National Bureau of Standards (which later became the National Institute of Standards and Technology, or NIST), and subsequently DES became a standard of the American National Standards Institute (ANSI) . There is a great deal to say about DES and its history, but my purpose here is not to describe the algorithm but simply to summarize its adaptation and use inside the Oracle database. This algorithm requires a 64-bit key, but discards 8 of them, using only 56 bits. An intruder would have to use up to 72,057,594,037,927,936 combinations to guess the key.

DES was an adequate algorithm for quite a while, but the decades-old algorithm shows signs of age. Today’s powerful computers might find it easy to crack open even the large number of combinations needed to expose the key.

Triple DES (DES3)

NIST went on to solicit development of another scheme based on the original DES that encrypts data twice or thrice, depending ...