# Proof of Replication

Juan Benet David Dalrymple Nicola Greco## Abstract

We introduce *Proof-of-Replication* (**PoRep**), a new kind of *Proof-of-Storage*, that can be used to prove that some data D has been *replicated* to its own uniquely dedicated physical storage. Enforcing unique physical copies enables a verifier to check that a prover is not deduplicating multiple copies of D into the same storage space. This construction is particularly useful in *Cloud Computing* and *Decentralized Storage Networks*, which must be transparently verifiable, resistant to Sybil attacks, and unfriendly to outsourcing.

This work (a) reviews *Proofs-of-Storage* and motivates use cases; (b) defines the novel *Proofs-of-Replication*, which can be *publicly verifiable, transparent, authenticated*, and *time-bounded*; (c) shows how to chain *Proofs-of-Replication* to establish useful *Proofs-of-Spacetime*.