With NIST’s formal establishment of post-quantum cryptography standards and their practical deployment, evaluating the security of the selected KEM standard Kyber has become increasingly important. As Kyber is poised for widespread adoption, assessing its resilience against practical threats like side-channel attacks is critical. Among these threats, key mismatch attacks represent a prominent class of side-channel vulnerabilities crucial for evaluating the security of lattice-based KEMs, especially Kyber. In this paper, we further propose a checking scheme tailored for a parallel key mismatch attack, which is proposed by Shao et al. at ASIACCS 2024. The core idea of our method is to leverage the initially recovered coefficients as prior information to verify their correctness and then selectively recover the coefficients identified as incorrect. To evaluate the effectiveness of our scheme, we conduct extensive software simulations against Kyber1024. Experiments demonstrate that when the oracle accuracy is \(99.8\%\) , \(99.5\%\) and \(99.0\%\) , the number of queries is reduced by \(44.97\%\) , \(42.46\%\) and \(38.31\%\) , respectively. Moreover, in real-world experiments conducted on an ARM Cortex-M4 development board with a Kyber implementation from the pqm4 public library, our scheme achieves a \(41.77\%\) reduction in the complexity of the query at an oracle accuracy of \(99.4\%\) .