BDABE - Blockchain-based Distributed Attribute based Encryption

Attribute Based Encryption (ABE) denotes asymmetric cryptographic schemes where key pairs are created for attribute owners and often applied to realize a fine-grained, cryptographic access control mechanism for outsourced data. Despite the benefits of ABE systems, there are still drawbacks when ABE systems are transformed into real world applications. Mainly, ABE systems suffer from non-efficiency or non-existence of revocation mechanisms and user key coordination problems. By introducing a consensus driven approach, we try to mitigate these issues in distributed systems. In this paper, we propose a collaborative attribute management protocol for Ciphertext-policy attribute-based encryption (CP-ABE) schemes based on our own scheme called a Blockchain-based Distributed Attribute Based Encryption (BDABE) scheme. Our construction realizes distributed issue, storage and revocation of private attribute keys by adding a consensus driven infrastructure, a blockchain. We enhance both security and efficiency of key management in distributed CP-ABE systems for the application of cloud data sharing.