2 Chapter 2. CPACF enhancements in System z9 In this chapter we describe the new CPACF functions supplied with the IBM System z9 109 processor and how they can be used. We discuss the following: Confirmation that CPACF facilities are available Description of the CPACF functions, highlighting the new functions for IBM System z9 109 Discussion of capabilities of the CPACF instruction set Description of clear-key processing Description of the AES algorithm Description of SHA-256 Considerations using CPACF with regard to LPAR We also include details of programs we used to test some of the new CPACF functions. The source code is provided in Appendix A, "CPACF programs" on page 103. © Copyright IBM Corp. 2005. All rights reserved. 13