Developer Reference for Intel® Integrated Performance Primitives Cryptography 2018
Some Intel IPP Cryptography functions use special structures to store function-specific (context) information. For example, the IppsRijndael128Spec structure stores a set of round keys, a set of round inverse keys, and key management information for the Rijndael cipher scheme with the block size equal to 128.
Two different kinds of context structures are used:
It is your application that defines the life cycle of the context: initialization, updating, and destruction.
Context structures are initialized with the initialization functions. For example, the ippsRijndael128CCMInit function initializes the user-supplied memory as the IppsRijndael128CCMState context.