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:
“When the wind carries a cry which is meaningful to human ears, it is simpler to believe the wind shares with us some part of the emotion of Being than that the mysteries of a hurricane’s rising murmur reduce to no more than the random collision of insensate molecules.”
—Norman Mailer (b. 1923)
“Hence that general is skilful in attack whose opponent does not know what to defend; and he is skilful in defense whose opponent does not know what to attack.”
—Sun Tzu (6th–5th century B.C.)