id description section req max_loop max_usage pos AK1 Functional Group Response Header H M 0 1 1 AK2 Transaction Set Response Header H O 0 1 2 SPE Security Protocol Error H O 0 1 3 APE Assurance Protocol Error H O 0 1 4 S4A Assurance Header Level 2 H O 2 1 5 SVA Security Value H O 0 1 6