In this paper, we propose a secure and scalable optical image encryption framework for pervasive computing environments by integrating chaotic cryptography, hybrid RSA-AES encryption, and blockchain-based trust anchoring. The system leverages Lorenz-based Double Random Phase Encoding (DRPE) to generate high-entropy chaotic masks for robust optical encryption. A hybrid cryptographic layer is employed, where the DRPE-encrypted image is secured using AES, and the session key is protected via RSA. Device enrolment, key authentication, and transaction logging are managed through smart contracts on a blockchain network, ensuring traceability and trust. Inter-device communication and storage are optimized using IPFS for decentralized access. Experimental results demonstrate the scheme’s resilience against statistical, brute-force, and differential attacks, making it well-suited for privacy-preserving image transmission in resource-constrained pervasive devices.