ParaSM2: Enhancing SM2 Cryptographic Performance via Parallel Restructuring of KDF and HASH

In the past decade, the high computational overhead of asymmetric cryptography has remained a central challenge in end-to-end secure communication systems. To mitigate the performance bottlenecks inherent in the full SM2 encryption and decryption workflow, this paper introduces ParaSM2, a parallel restructuring optimization framework tailored for SM2-based cryptographic operations. ParaSM2 exploits the observed 2:1 processing ratio between KDF and HASH to perform cross-component parallel restructuring and applies fixed-prefix reuse together with dynamic task parallelism to eliminate 39.7% of redundant KDF computations. Furthermore, a vectorized reconstruction of the HASH message extension is incorporated to leverage SIMD parallel acceleration, thereby substantially enhancing throughput. Experimental evaluations against SM4-GCM and SM4-CBC on data blocks larger than 64 KB demonstrate that ParaSM2 achieves up to a 5.1× performance improvement on both x86 and ARM architectures, effectively reducing end-to-end latency and providing a scalable pathway for algorithmic optimization in cryptography across heterogeneous platforms.