English

Pitfalls of Provably Secure Systems in Internet The Case of Chronos-NTP

Cryptography and Security 2020-10-19 v1

Abstract

The critical role that Network Time Protocol (NTP) plays in the Internet led to multiple efforts to secure it against time-shifting attacks. A recent proposal for enhancing the security of NTP with Chronos against on-path attackers seems the most promising one and is on a standardisation track of the IETF. In this work we demonstrate off-path attacks against Chronos enhanced NTP clients. The weak link is a central security feature of Chronos: The server pool generation mechanism using DNS. We show that the insecurity of DNS allows to subvert the security of Chronos making the time-shifting attacks against Chronos-NTP even easier than attacks against plain NTP.

Keywords

Cite

@article{arxiv.2010.08460,
  title  = {Pitfalls of Provably Secure Systems in Internet The Case of Chronos-NTP},
  author = {Philipp Jeitner and Haya Shulman and Michael Waidner},
  journal= {arXiv preprint arXiv:2010.08460},
  year   = {2020}
}