Message Integrity

The quality of a transmitted message, such that its recipients can be assured that the contents of the message have not been tampered with or altered since the time it was transmitted by the sender. One common approach is to use a one-way hash function that combines all of the bytes in the message to produce a message digest that is impossible to reverse and then make a digital signature of this hash value by the sender. Another method involves combining message bytes with a key value known only to the sender and recipient in a hash function.