[agl]

I do not represent an NVLAP lab, but I'd question whether this would pass strict muster for FIPS given IG A.5: https://csrc.nist.gov/csrc/media/projects/cryptographic-modu...

(Disclaimer: author of AES-GCM-SIV. Not casting shade here, it's a fair idea! But not sure about the specific FIPS claim.)

[api]

I'm not 100% sure either and am looking into it. FIPS is a rats nest and it may "depend." At this point I was just looking for basic feedback as to whether anyone could see any obvious problems. One person did suggest using a different AES key for each operation, which costs next to nothing and is probably good practice.

Edit: plan is to re-key often enough than plain GCM with 64-bit tags would be "fine" from a FIPS point of view. The goal here is to do better than the FIPS requirement by closing a potential attack vector.