Security

Non Observability in the Random Oracle Model

Date Added: Dec 2012
Format: PDF

The Random Oracle Model, introduced by Bellare and Rogaway, provides a method to heuristically argue about the security of cryptographic primitives and protocols. The basis of this heuristic is that secure hash functions are close enough to random functions in their behavior, and so, a primitive that is secure using a random function should continue to remain secure even when the random function is replaced by a real hash function. In the security proof, this setting is realized by modeling the hash function as a random oracle. However, this approach in particular also enables any reduction, reducing a hard problem to the existence of an adversary, to observe the queries the adversary makes to its random oracle and to program the responses that the oracle provides to these queries.