Proofs of Space

Proofs of Space (PoS) is a blockchain consensus mechanism made to be an alternative to Proof-of-Work. Proofs of Space (PoS) consensus mechanisms require service requestors to dedicate disk space instead of computation. Proofs of Space (PoS) consensus mechanisms assume users have a significant amount of free disk space and can essentially us a PoS for free because PoS requires disk space and not computational power or energy.

A PoS protocol has two distinct phases that occur between a prover (P) and a verifier (V). The first phase is called the initialization phase. The initialization phase requires the prover (P) to store specific data (F) of a specific size (N), while the verifier (V) only holds a small amount of information. The second phase of a PoS protocol is called the proof execution phase. The proof execution phase is initialized by the verifier (V) and prompts the prover to send back random bits of its stored data (F) to validate it stored the desired information. The proof of execution phase ends when the verifier (V) accepts or rejects information it receives from the prover (P).