Hardening GNSS Time - A Method to Counter Spoofing Attacks.pdf

1、Describing a Method to Counter GNSS Spoofing AttacksHardening GNSS TimeHeiko Gerstung,Managing Director,MeinbergHardening GNSS TimeA Method to Counter Spoofing AttacksSECURITY AND DATA PROTECTIONTIME APPLIANCESGlobal Navigation Satellite Systems(GNSS)like GPS,Galileo or Beidou are used globally for

2、positioning and navigationCalculation of the position is done by comparing signal-time-of-arrival of multiple satellites Satellites use very stable on-board clocks GNSS based timing is utilized in highly critical applications:Power grid protection,control and steering Telecommunication networksFinan

3、cial datacentersBroadcast and media networksDefense applicationsGNSS as a Source of TimeSignals are very weak because the satellites are far away and power-constrainedGPS satellites are 22,000 km/13,700 miles away“Jamming”:transmitting a radio signal that over-powers the original signals and prevent

4、s the receiver from receiving them(DoS)Non-military GNSS signals are unprotected(think of telnet or http)“Spoofing”:generating GNSS signals with modified content and“over-powering”the original signals(MITM)Estimated time of arrival is the keyDelaying signals will result in wrong calculations“Meaconi

5、ng”/“Delay Attacks”:re-transmit original signal after a delayGNSS VulnerabilitiesDoS attack preventing a GNSS timing device to receive GNSS signalsDefense strategies:multiple sources of time(e.g.PTP over a network connection)Good holdover performanceHoldover:without any additional input,system runs

6、on its internal clockPerformance(Stability)of the clock and requirement of the application(maximum time error tolerated)define how long the application can continue to functionJammingMITM attack delaying the signals,over-powering the original signals with the delayed(re-)generated transmission.Defen