The AH header consists of the following fields:
In our abstract packet format this is:
where data-list is the entire packet.
Since all fields in a packet using the AH header are included in the hash-data, it is easy to prove that integrity and authentication are provided over the entire packet. AH may also be used in tunnel mode (see ) but again since all fields are covered by an authenticator, such as a hash, it is easy to show that both integrity and authentication are provided for the packet.