January 29, 2002
Practical Aspects of Modern Cryptography
32
A Cryptographic Hash:
SHA-1
n
Depending on the round, the “non-linear”
function
f
is one of the following.
n
n
f(X,Y,Z) = (X
Ù
Y)
Ú
((
Ø
X)
Ù
Z)
n
f(X,Y,Z) =
(X
Ù
Y)
Ú
(X
Ù
Z)
Ú
(Y
Ù
Z)
n
f(X,Y,Z) = X
Å
Y
Å
Z