Oblivious assignment with m slots

Preserving anonymity and privacy of customer actions within a complex software system, such as a cloud computing system, is one of the main issues that must be solved in order to boost private computation outsourcing. In this paper, we propose a coordination paradigm, namely oblivious assignment with m slots of a resource ℛ (with m ≥ 1), allowing processes to compete to get a slot of ℛ while ensuring, at the same time, both fairness of resource allocation and obliviousness, that is, the impossibility for any process to infer which slot of ℛ is assigned to any other process. We study oblivious assignment with m slots solvability issues based on the message pattern of the algorithm. We also present a distributed algorithm solving oblivious assignment with m slots within a distributed system, assuming the existence of at least two honest processes and m ≤ n (where n is the number of processes). The algorithm is based on a rotating token paradigm and employs an adaptation of the ElGamal encryption scheme to work with multiple parties and to ensure obliviousness of the assignment. Finally, the correctness of the algorithm is formally proved.