A security risk of depending on synchronized clocks

✍ Scribed by Gong, Li

• Book ID: 121207768
• Publisher: Association for Computing Machinery
• Year: 1992
• Tongue: English
• Weight: 405 KB
• Volume: 26
• Category: Article
• ISSN: 0163-5980
• DOI: 10.1145/130704.130709

✦ Synopsis

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.