© 2021, Taiwan Ubiquitous Information CO LTD. All rights reserved.Due to its resource-friendly nature, symmetric-key based authentication methods are prioritized over public key infrastructure for employment in resource-constrained devices. Recently, a large number of symmetric-key based authentication protocols are proposed; however, the real progress is still marginal owing to repeated mistakes. Specifi-cally, the emphasis on anonymity and privacy alongside the computational and commu-nicative efficiencies has introduced some design flaws. The Identity De-Synchronization (ID-S) is one of such important issues that surfaced owing to such design flaws. This article aims to emphasize the causes and pitfalls of ID-S and for this purpose, a recent symmetric-key based authentication for the internet of vehicles (IoV) is analyzed. Pre-cisely, it is to show in this article that the scheme of Xu et al. is vulnerable against ID-S under the widely used DY adversarial model. The article also proposes the avail-able remedies to avoid ID-S and proposes an improved scheme.