1
Q
unkeyed hash function
A
function from all possible messages to finite set of possible message digests
2
Q
family of keyed hash function
A
four-tuple
X possible messages
Y finite set of possible authentication tags
for each k, there is a hash function
3
Q
message digest code
A
unkeyed hash function
4
Q
compression
A
maps x to y of fixed length
5
Q
computability
A
h(x) is easy to compute
6
Q
Message digest strengthening
A
addition of length-block x_(r+1) containing the binary representation of b
