Department of Computer Science and Technology

Technical reports

Are timestamps worth the effort?
A formal treatment

Giampaolo Bella, Lawrence C. Paulson

September 1998, 12 pages


Theorem proving provides formal and detailed support to the claim that timestamps can give better freshness guarantees than nonces do, and can simplify the design of crypto-protocols. However, since they rely on synchronised clocks, their benefits are still debatable. The debate should gain from our formal analysis, which is achieved through the comparison of a nonce-based crypto-protocol, Needham-Schroeder, with its natural modification by timestamps, Kerberos.

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BibTeX record

  author =	 {Bella, Giampaolo and Paulson, Lawrence C.},
  title = 	 {{Are timestamps worth the effort? A formal treatment}},
  year = 	 1998,
  month = 	 sep,
  url = 	 {},
  institution =  {University of Cambridge, Computer Laboratory},
  number = 	 {UCAM-CL-TR-447}