Limits on the Usefulness of Random Oracles

In the random oracle model, parties are given oracle access to a random function (i.e., a uniformly chosen function from the set of all functions), and are assumed to have unbounded computational power (though they can only make a bounded number of oracle queries). This model provides powerful properties that allow proving the security of many protocols, even such that cannot be proved secure in the standard model (under any hardness assumption). The random oracle model is also used for showing that a given cryptographic primitive cannot be used in a black-box way to construct another primitive; in their seminal work, Impagliazzo and Rudich [STOC ’89] showed that no key-agreement protocol exists in the random oracle model, yielding that key-agreement cannot be black-box reduced to one-way functions. Their work has a long line of followup works (Simon [EC ’98], Gertner et al. [STOC ’00] and Gennaro et al. [SICOMP ’05], to name a few), showing that given oracle access to a certa...

• Type: Journal
• Year: 2016
• Where: JOC
• Authors: Iftach Haitner, Eran Omri, Hila Zarosim
• Keywords: JOC 2016