BlockStore: A Secure Decentralized Storage Framework on Blockchain

In order to ensure faster audits, higher transparency and security, many applications are being designed using blockchains. We propose BlockStore, a secure decentralized storage framework using blockchain technology. The primary motivation is efficient utilization of storage resources of users. Users often have un-utilized or underutilized storage in their devices. They can choose to host their storage resources when they are not in use. Users rent storage from the host for a fee for a fixed period of time and release back after the time expires. BlockStore keeps track of un-utilized storage of hosts in Space Wallet, a structure that helps in assigning storage to renters on request. The ownership of storage can be proved by logging all storage transactions in a public ledger (the blockchain), which can be verified by any user. A host cannot host the same storage to two users at the same time, nor can it tamper with the data of the renter. Renters cannot frame a host of cheating. BlockStore uses proofs of storage and data possession to verify that the hosts do not tamper with data and penalizes parties for misbehavior. Users can encrypt data for privacy. Payment and penalty are handled using smart contracts. BlockStore differs from existing solutions, by providing stronger audit that detects and penalizes misbehaving parties earlier than existing schemes.