The Arm Security Algorithm Accelerators are hardware blocks to be used with Armv8-A Cortex-A, Cortex-AE, and Neoverse CPUs to support the Armv8-A Cryptography Extensions. To download the hardware block, go to processor section:

Cortex-A | Neoverse

Cortex-A 

Download the Arm Security Algorithm Accelerators for Cortex-A series processors

Neoverse

Download the Arm Security Algorithm Accelerators for Neoverse series processors