‘ve been exploiting the cryptographic capabilities of the i5/OS operating system in a number of utilities and business systems. One of the facilities involved is the Generate Pseudorandom Numbers API. For OPM, this is QC3GENRN, for ILE it is Qc3GenPRNs. The API basically returns a pseudorandom binary stream of the specified length, which then can be used as “salt” for a cryptographic encrypt or decrypt operation. For example, it can be used as a random number in a program function requiring a feature such as choosing 100 random customers for statement verification during a financial audit process.
A salt or initialization vector is an initial chaining value used in the encryption process to prevent the same clear text from producing the same cipher string. Which, of course, could compromise the confidentiality of the encrypted data.