If you have only a clear key, you are not limited to using only the encode and decode callable services.

• You can pass your clear key to the clear key import service, and get back a token that will allow you to use the encipher and decipher callable services.
• On an IBM zSeries 990 and subsequent releases, consider using the Symmetric Key Decipher service (Symmetric Key Decipher (CSNBSYD or CSNBSYD1 and CSNESYD or CSNESYD1)).