With the rapid growth of Internet of Things (IoT) applications and decentralized data-driven systems, secure and flexible data sharing remains a critical challenge. Identity-Based Proxy Re-Encryption (IB-PRE) is an effective cryptographic primitive for enabling fine-grained access delegation without exposing plaintext data. However, existing IB-PRE schemes remain vulnerable to algorithm substitution attacks (ASA), malicious key generation, inefficient ciphertext management, and the lack of practical revocation mechanisms. To address these limitations, we propose a blockchain-based revocable identity-based proxy re-encryption scheme with cryptographic reverse firewalls (BRIBPR-CRF) for secure... More >