Privacy Preservation for On-Chain Data in the Permission less Blockchain using Symmetric Key Encryption and Smart Contract

Blockchain technology provides several suitable characteristics such as immutability, decentralization and verifiable ledger. It records the transactions in a decentralized way can be integrated into fields like eHealth, e-Government smart cities etc. However, blockchain has privacy security issues, one of them is on-chain data privacy. To deal with this issue we provide privacy-preserving solution for permission less to empower user take control transaction open This work focuses on designing developing peer-to-peer system using symmetric cryptography ethereum contract. In scheme, create contracts interaction provider, consumer, access list. Data providers register authorized users consumers check their validity After successful validation, request key from secret information. Based contract that created between provider consumer executed send accessing The proposed model are modeled solidity, performance assessed Ropsten test network.