This paper surveys protocols that verify remote data possession. These protocols have been proposed as a primitive for ensuring the long-term integrity and availability of data stored at remote untrusted hosts. Externalizing data storage to multiple network hosts is becoming widely used in several distributed storage and P2P systems, which urges the need for new solutions that provide security properties for the remote data. Replication techniques cannot ensure on their own data integrity and availability, since they only offer probabilistic guarantees. Moreover, peer dynamics (i.e., peers join and leave at any time) and their potential misbehavior (e.g., free-riding) exacerbate the difficult challenge of securing remote data. To this end, remote data integrity verification protocols have been proposed with the aim to detect faulty and misbehaving storage hosts, in a dynamic and open setting as P2P networks. In this survey, we analyze several of these protocols, compare them with respect to expected security guarantees and discuss their limitations.
