Conditions of a secure hash function · Preimage Find x such that h(x)=y, given y and the function fO one-way(preimage resistant) Second preimage Find x!=x, such that h(x)=h(x), given x and the function ho weak collision resistance( Second preimage resistant) Collision Find h(x)=h(x)such that x!=x, given function ho strong collision resistance( Collision resistant)7 Conditions of a secure hash function • Preimage – Find x such that h(x) = y, given y and the function f(). – one-way(preimage resistant) • Second Preimage – Find x’ != x, such that h(x) = h(x’), given x and the function h(). – weak collision resistance(Second preimage resistant) • Collision – Find h(x) = h(x’) such that x != x’, given function h() – strong collision resistance(Collision resistant)