Ensuring the integrity of critical data is essential for maintaining security and trust across diverse computing environments. Conventional cryptographic hash functions provide reliable integrity guarantees. However, they incur significant computational overhead when protecting large volumes of data and are also vulnerable if reference hash values are tampered with. To address these limitations, this paper proposes PACIV (Pointer Authentication Code based Integrity Verification), a high-performance and secure system for critical data integrity verification that leverages ARM Pointer Authentication Code (PAC). By chunking data into 64-bit units and utilizing actual hardware PAC instructions, the system is designed to provide fine-grained integrity verification while maintaining cryptographic strength. In particular, our system targets integrity verification of critical data, such as kernel configuration data, which must remain trustworthy during system operation. Through this approach of using hardware-based cryptographic computation and secure key storage, the system provides stronger protection than software-based hash functions. Experimental evaluations demonstrate that the proposed system achieves average performance improvements of 23.81× in generation and 26.14x in verification compared to traditional non-accelerated SHA-256-based verification.