US 12,248,409 B2
Apparatus and method of controlling access to data stored in a non-trusted memory
Hector Montaner Mas, Cambridge (GB); Andreas Lars Sandberg, Cambridge (GB); and Roberto Avanzi, Cambridge (GB)
Assigned to Arm Limited, Cambridge (GB)
Appl. No. 17/756,877
Filed by Arm Limited, Cambridge (GB)
PCT Filed Nov. 12, 2020, PCT No. PCT/GB2020/052882
§ 371(c)(1), (2) Date Jun. 3, 2022,
PCT Pub. No. WO2021/116655, PCT Pub. Date Jun. 17, 2021.
Claims priority of application No. 1918126 (GB), filed on Dec. 10, 2019.
Prior Publication US 2023/0113906 A1, Apr. 13, 2023
Int. Cl. G06F 12/00 (2006.01); G06F 12/0866 (2016.01); G06F 12/14 (2006.01)
CPC G06F 12/1458 (2013.01) [G06F 12/0866 (2013.01); G06F 12/1441 (2013.01)] 20 Claims
OG exemplary drawing
 
1. An apparatus comprising:
memory access circuitry to control access to data stored in a non-trusted memory;
memory security circuitry to verify integrity of data stored in the non-trusted memory; and
a trusted storage;
the memory security circuitry having authentication code generation circuitry to generate authentication codes to be associated with the data stored in the non-trusted memory, for use when verifying the integrity of the data;
wherein the authentication code generation circuitry is arranged, for a given block of data for which an associated authentication code is to be generated:
to generate as the associated authentication code a first authentication code with a first size to be compared with a first comparison authentication code to verify the integrity of the given block of data when the associated authentication code is to be stored in the non-trusted memory, and
to generate as the associated authentication code a second authentication code with a second size less than the first size to be compared with a second comparison authentication code to verify the integrity of the given block of data when the associated authentication code is to be stored in the trusted storage.