Open Access
Network Time Protocol Version 4: Autokey Specification
David L. Mills,Brian Haberman +1 more
- Vol. 5906, pp 1-58
TLDR
This memo describes the Autokey security model for authenticating servers to clients using the Network Time Protocol (NTP) and public key cryptography, which is based on the premise that IPSEC schemes cannot be adopted intact.Abstract:
This memo describes the Autokey security model for authenticating
servers to clients using the Network Time Protocol (NTP) and public
key cryptography. Its design is based on the premise that IPSEC
schemes cannot be adopted intact, since that would preclude stateless
servers and severely compromise timekeeping accuracy. In addition, PKI
schemes presume authenticated time values are always available to
enforce certificate lifetimes; however, cryptographically verified
timestamps require interaction between the timekeeping and
authentication functions. This memo includes the Autokey requirements
analysis, design principles and protocol specification. A detailed
description of the protocol states, events and transition functions is
included. A prototype of the Autokey design based on this memo has
been implemented, tested and documented in the NTP Version 4 (NTPv4)
software distribution for Unix, Windows and VMS at http://www.ntp.org.read more
Citations
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Proceedings ArticleDOI
Keeping Authorities "Honest or Bust" with Decentralized Witness Cosigning
Ewa Syta,Iulia Tamas,Dylan Visher,David Isaac Wolinsky,Philipp Jovanovic,Linus Gasser,Nicolas Gailly,Ismail Khoffi,Bryan Ford +8 more
TL;DR: CoSi, a scalable witness cosigning protocol ensuring that every authoritative statement is validated and publicly logged by a diverse group of witnesses before any client will accept it, is introduced, offering the first transparency mechanism effective against persistent man-in-the-middle attackers.
Security Requirements of Time Protocols in Packet Switched Networks
TL;DR: This document defines a set of security requirements for time protocols, focusing on the Precision time Protocol (PTP) and the Network Time Protocol (NTP), and discusses the security impacts of time protocol practices, the performance implications of external security practices on time protocols and the dependencies between other security services and time synchronization.
Proceedings ArticleDOI
Time synchronization security using IPsec and MACsec
TL;DR: This paper describes the common deployment scenarios for PTP using two off-the-shelf security protocols, IPsec and MACsec, and presents a security threat analysis under these scenarios.
Journal ArticleDOI
Attacking NTP's Authenticated Broadcast Mode
Aanchal Malhotra,Sharon Goldberg +1 more
TL;DR: In this article, the authors present a replay attack that allows an on-path attacker to indefinitely stick a broadcast client to a specific time, and a denial-of-service (DoS) attack that prevents an offpath attacker from ever updating its system clock; the attacker sends the client a single malformed broadcast packet per query interval.
Book ChapterDOI
The Security of NTP’s Datagram Protocol
Aanchal Malhotra,Matthew Van Gundy,Mayank Varia,Haydn Kennedy,Jonathan Gardner,Sharon Goldberg +5 more
TL;DR: In this article, the authors take a new look at the security of NTP's datagram protocol and show that the NTP specifications do not sufficiently respect the conflicting security requirements of different NTP modes, and the mechanism NTP uses to prevent off-path attacks.
References
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TL;DR: This document describes an updated version of the Encapsulating Security Payload (ESP) protocol, which is designed to provide a mix of security services in IPv4 and IPv6.
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