Tomer Gal, Fujiao Ji, Doowon Kim et al.
Google Safe Browsing (GSB) and DNS resolution operate concurrently during browser navigation, yet their packet-level synchronization remains understudied. This work characterizes the timing gap (\(Δ_{time}\)) between GSB-related query close events and parallel DNS resolution responses, identifying a consistent temporal offset with potential security relevance. Using packet-capture analysis across general and CNAME-domain datasets, we observe positive timing gaps in approximately 79\% of measurements. In these instances, DNS responses lag behind GSB-related query closures with median delays of 67-79 ms and maximum delays surpassing 2,400 ms. These empirical results highlight a measurable window within the browsing workflow. We suggest that such temporal inconsistencies, particularly in complex CNAME-domain resolutions, may create a security-relevant timing precondition under DNS-manipulation threat models. These results provide a foundation for further research into timing-based risks and mitigations in browser safety mechanisms.