Deriving Key1 and Key2 from a 16-Byte Key

Let Key1 be the first 7 bytes of the 16-byte key.

Let Key2 be the next 7 bytes of the 16-byte value. For example, consider a zero-base-index array of 16 bytes called KeyArray that contains the 16-byte key. Key2 is composed of the bytes KeyArray[7] through KeyArray[13], inclusive.

Note A consequence of this derivation is that the fifteenth and sixteenth bytes are ignored.