Decentralized Storage Networks
Decentralized Storage Networks (DSNs) offer Storage-as-a-Service solutions via a network of independent storage providers that do not rely on a single coordinator.
Guarantees for the data
Protocols that guarantee the data storage are called Proofs-of-Storage and they come in different flavours.
Proofs-of-Storage schemes such as Provable Data Possession (PDP) and Proof-of-Retrievability (PoR) schemes allow a user (the verifier V) who outsources data D to a server (the prover P) to repeatedly check if the server is still storing D.
The user can verify the integrity of the data outsourced to a server in a very efficient way, more efficiently than downloading the data. The prover generates probabilistic proofs of possession by sampling a random set of blocks and transmits a small constant amount of data in a challenge/response protocol with the user.
These proofs solve partially the problem of untrusted delegated storage of data. However, PDP/PoR protocols certify data integrity and availability only at the time a valid proof is processed. Between two proofs, there is nothing that can be guaranteed about the permanent storage or availability of the outsourced data.
A way to guarantee continuous data availability is by performing frequent checks over time. However, this requires that users (the verifiers) are online when sending sequential challenges to the storage server and the communication and computation costs for these verifiers increases with the number of queries.
In a DSN
- clients pay to store and retrieve data
- Storage Providers earn tokens by offering storage
- Retrieval Providers earn tokens by serving data