Traceable and Revocable Broadcast Encryption Scheme for Preventing Malicious Encryptors

Under the paradigm of the Internet of Things (IoT), the processing of large-scale data not only imposes higher demands on data-sharing efficiency but also increases the risk of user privacy leakage. To address these challenges, this paper proposes a blockchain-assisted traceable and revocable broadcast encryption scheme for preventing malicious encryptors (BATR). To resist trapdoor attacks by malicious encryptors, the scheme utilizes the uniform distribution property of hash function outputs to generate the random numbers required for the encryption algorithm. To block malicious users from leaking private keys, which attackers could exploit to construct piracy decoders with decryption capabilities, the scheme enhances the traditional broadcast encryption system by incorporating public tracing and revocation mechanisms. The scheme employs personalized transmission technology, allowing data owners to share public data with a set of authorized users while also sharing personalized data with specific authorized users. Additionally, users communicate using pseudonyms to ensure that their real identities are not accessible to third parties, thereby meeting privacy protection requirements. With the assistance of blockchain, trusted authorities and users can invoke smart contract interfaces to trigger blockchain peer nodes to execute smart contracts, thereby acquiring or updating identity authentication information stored on the blockchain to achieve secure authentication. This paper provides an analysis of the correctness and security of BATR, demonstrating that BATR satisfies chosen-ciphertext security under the Random Oracle Model. We also present performance evaluations and describe the experimental setup used to obtain operation-time baselines. Finally, this paper conducts a performance analysis of the BATR scheme, which exhibits high computational efficiency and compact communication bandwidth, resulting in significant performance improvements.