/AES=keyword

    Specifies that you must use AES algorithm. If this qualifier is
    not specified, the DES algorithm is used by default. You can use
    the following keywords with the /AES qualifier:

    Keyword           Description
    AES128(default)   Indicates that 128 bits AES key value is used.
                      The MAC value generated in this mode is of
                      size 128 bits.
    AES192            Indicates that 192 bits AES key value is used.
                      The MAC value generated in this mode is of
                      size 192 bits.
    AES256            Indicates that 256 bits AES key value is used.
                      The MAC value generated in this mode is of
                      size 256 bits.