In the dynamic and resource-constrained landscape of IoT, securing sensitive data access is paramount. This paper introduces an innovative access control scheme (ACPRE) blending conditional attribute-based proxy re-encryption with inner product encryption, tailored for IoT security needs. ACPRE integrates attribute-based conditions, expands plaintext space, and restricts proxy privileges, bolstering access control. Leveraging inner product encryption, it confines decrypted information to inner product values, ensuring data confidentiality. By limiting proxies’ transformation abilities, ACPRE prevents unauthorized data alterations. It offers a secure, flexible solution for data access management, allowing only entities with specific attributes to utilize inner product values. ACPRE’s lattice-based construction enables resistance against quantum attacks and achieves honestly re-encryption attacks security, fostering robust, privacy-aware IoT ecosystems. Detailed security proofs and experimental validation underscore its efficacy.