January 29, 2002
Practical Aspects of Modern Cryptography
21
One-Way Hash Functions
n
There are many measures for one-way hashes.
n
n
Non-invertability:
given
y
, it’s difficult to
find any
x
such that
H(x) = y
.
n
n
Collision-intractability:
one cannot find a
pair of values
x
¢
¹
x
such that
H(
x
) = H(
x
¢
)
.