The random oracle model This is an idealized model in which captures the concept of a hash function in an ideal fashion ahash function h:Ⅹ→ Y is chosen at random from the set fx,y of all functions from x to y Given x, its hash y can only be obtained from an oracle8 The random oracle model This is an idealized model in which captures the concept of a hash function in an ideal fashion. • A hash function h: X → Y is chosen at random from the set F X,Y of all functions from X to Y. Given x, its hash y can only be obtained from an oracle