In cryptography, a collision attack on a cryptographic hash tries to find two arbitrary inputs that will produce the same hash value, i.e. a hash collision. In contrast to a preimage attack, neither the hash value nor one of the inputs is specified.
There are roughly two types of collision attacks:
- Collision attack
- Find two arbitrary different messages m1 and m2 such that hash(m1) = hash(m2).
- Chosen-prefix collision attack
- Given two different prefixes p1, p2 find two appendages m1 and m2 such that hash(p1 ∥ m1) = hash(p2 ∥ m2) (where ∥ is the concatenation operation).
Read more about Collision Attack: Classical Collision Attack, Chosen-prefix Collision Attack, Attack Scenarios
Famous quotes containing the words collision and/or attack:
“I know my fate. One day my name will be tied to the memory of something monstrous—a crisis without equal on earth, the most profound collision of conscience, a decision invoked against everything that had previously been believed, demanded, sanctified. I am no man, I am dynamite!”
—Friedrich Nietzsche (1844–1900)
“It is well worth the efforts of a lifetime to have attained knowledge which justifies an attack on the root of all evil—viz. the deadly atheism which asserts that because forms of evil have always existed in society, therefore they must always exist; and that the attainment of a high ideal is a hopeless chimera.”
—Elizabeth Blackwell (1821–1910)