Deliberately narrower than SegmentIntegrityAlgorithm: AES-GCM never
processes the aggregate hash, so there is no tag to extract and GMAC would
degenerate into copying the last segment hash — a keyless, forgeable value.
The type carries the invariant so a root algorithm cannot even be typed as
'GMAC'. See rootIntegrity.
Algorithms usable for the root signature.
Deliberately narrower than SegmentIntegrityAlgorithm: AES-GCM never processes the aggregate hash, so there is no tag to extract and
GMACwould degenerate into copying the last segment hash — a keyless, forgeable value. The type carries the invariant so a root algorithm cannot even be typed as'GMAC'. See rootIntegrity.