Variación del modo de cifrado CTR incluyendo un
mecanismo de autenticación basado en una función resumen.
GCM combines a variation of
the Counter Mode for encryption with an authentication mechanism that is based
on a universal hash function. The underlying (approved) block cipher must have
a block size of 128 bits (i.e., the AES algorithm) and the size of the
authentication tag is 96-128 bits.