A security risk of depending on synchronized clocks
Li Jing Gong · ACM SIGOPS Operating Systems Review · 1992
Many algorithms or protocols, in particular cryptographic protocols such as authentication protocols, use synchronized clocks and depend on them for correctness. This note describes a scenario where a clock synchronization failure renders a protocol vulnerable to an attack even after the faulty clock has been resynchronized. The attack exploits a postdated message by first suppressing it and replaying it later.