Perfectly Secure Oblivious Priority Queue

An Oblivious Priority Queue (OPQ) is a cryptographic primitive that enables client to outsource its data dishonest server, and also securely manage the according priority queue algorithm. Though first OPQ achieves perfect security, it supports only two operations; Inserting an element extracting top-priority element, which are minimal requirement for queue. In addition, this allows adversary observe operations in progress, leaks exact number of elements structure. On other hand, there many subsequent works OPQs implement additional queue, hide running operations, improve efficiency. recent realize optimal efficiency, all them achieve statistical or computational security. Aiming reconcile security with functions (including operation hiding) supported by OPQs, we construct novel perfectly secure can simulate following while hiding one progress; one, deleting modifying element. The efficiency our scheme O(log2 N), larger than best known statistically but same as scheme.