GCMmodus
GCMmodus is a term used in cryptography discussions to refer to a hypothetical variant of the Galois/Counter Mode (GCM) of operation for block ciphers. It is not part of any official standard and has no universally accepted specification. In published discussions, GCMmodus is described as exploring modifications to the authentication component of GCM—most commonly the GHASH step or the finite-field mathematics—alongside potential changes to nonce handling and performance characteristics, while keeping the general counter-mode encryption framework intact.
In its proposed form, GCMmodus would still provide both confidentiality and authenticity as an AEAD scheme,
Security considerations for any GCMmodus-like construction mirror those of GCM: the underlying cipher must be secure,