There are two options when considering AES-GCM key storage; battery backed RAM (BBRAM) or eFUSE.
RECOMMENDED: When selecting the BBRAM or eFUSE storage options, it is highly recommended that you consider the advantages and disadvantages of each option and which option fits your design requirements best.
The following sections detail each of their respective advantages and disadvantages. Additional information on each of these storage options can be found in the UltraScale Architecture Configuration User Guide (UG570) [Ref 3] .