One feature pertains to a mechanism to secure a data structure by using a computationally efficient algorithm. A plurality of keys and/or masks may be pre-generated upon boot-up or initiation of a session. An authentication code may be computed for each data structure (e.g., memory block or header block) by selecting a subset of the plurality of pre-generated keys and/or a mask from the plurality of pre-generated masks. The authentication code may be stored within the data structure for future verification of the integrity of the data structure. The keys and/or masks used for all authentication codes (e.g., for other data structures) may be selected from the same plurality of keys and/or masks during the same cycle or session.