Blockchain-Based Multi-Party Authorization for Accessing IPFS Encrypted Data

Abstract

Multi-party authorization (MPA) typically involves multiple parties to control and grant access to shared data. MPA is used to solve the insider's attack problem by ensuring that a single authority or party is not acting alone. Currently, almost all existing implementations of MPA are centralized and fall short in providing logs and events related to provenance of granting permissions in a trusted, secure, immutable, auditable, and decentralized manner. Moreover, for sharing data, proxy re-encryption algorithms are often used to give secure access to encrypted shared data. These schemes and algorithms are also centralized and cannot be trusted. In this paper, we propose a fully decentralized blockchain-based solution in which MPA is implemented using Ethereum smart contracts, and proxy re-encryption algorithms (which are computationally expensive) are implemented using multiple oracles to give access to encrypted shared data stored on a public and decentralized storage platform, such as the Interplanetary File Systems (IPFS). The smart contracts help to validate results based on the majority of encrypted results determined by the oracles. For this, we incorporate reputation mechanisms in the proposed smart contracts to rate the oracles based on their malicious and non-malicious behaviors. We present algorithms along with their full implementation, testing, and validation details. We evaluate the proposed system in terms of security, cost, and generalization to show its reliability and practicality. We make the smart contract source code publicly available on Github.

Decentralized Consensus Blockchain and IPFS-Based Data Aggregation for Efficient Data Storage Scheme

“…A fully decentralized approach for solving blockchainbased issues was suggested in [30] which were implemented with the use of Ethereum smart contract approach and the proxy re-encryption technique that were expensive computationally by means of multiple oracles for giving encrypted shared data storage access on the decentralized and public storage platforms like IPFS. e smart contracts aids in validating the outcomes depending on the encrypted outcome majority that were determined by oracles.…”

Developing Data Integrity in an Electronic Health Record System using Blockchain and InterPlanetary File System (Case Study: COVID-19 Data)

“…Currently, the size of the data stored in a block on the blockchain is only about 1MB, so it is not easy to store large amounts of data [32]. The data uploaded to IPFS is encrypted with a symmetric key, which is encrypted with a public key [33]. IPFS is not only a type of peer-to-peer file sharing system but can also be used for other needs.…”

COVID-19 Contact Tracing Using Blockchain

“…Specifically, in our use case scenario, only an oracle whose result matches with the majority of oracles’ results is considered the winning oracle and is rewarded for its timely and accurate response. Oracles should be rewarded and penalized based on their behavior and output results [28] . This is done through digital assets, e.g., Ether and reputation systems.…”