I've just read Column Encryption in IBM DB2 UDB for iSeries. What is the encryption algorithm used?
The SQL Encrypt scalar function uses an RC2 block cipher with padding, the 128 bit key is derived from the password using an MD5 message digest. Support for an SQL encryption function using Triple DES is being worked on for the next release.

Triple DES encryption is available on V5R3 via the cryptographic APIs in the operating system.

This was first published in October 2005