Data resilience: protection of a CBTC system from hackers

Author: Henry Cheung
Day: Aspect Day One
Session: Cyber Resilience

The signaling system has gone a long way from semaphore to
colour lights to electronics interlocking and analogue based
automatic train protection to the modern day communication
based train control (CBTC) system. The means of communication
for a CBTC system also evolved from inductive loop or track
circuit based to dedicated radio to the more commonly adopted
WiFi based system based on IEEE 802.11 international
standard.The subject of potential cyber-attack on a CBTC system
based on a publicly accessible communication system using off
the shelf equipment and devices has been widely discussed at
various forums, seminars, conferences and discussion groups.
Signalling system suppliers have incorporated into their design
various measures to protect the CBTC system from unauthorized
access and so far these protection measures seem to be
effective.In addition to the defensive protection, the IT industry
has developed many standards such as IEC 62443 series and ISO
15408 with an attempt to detect potential intrusion into the
system by hackers and report or eliminate these threats before
they become an issue.This paper attempts to review the ways
hackers would attack the CBTC systems: from wifi access points
installed along the trackside, from local area network portals at
stations, and even from virus apps hidden in the mobile phones of
the train driver; the counter-measures available for the systems
to defend themselves from being hacked: from fire-walls installed
around the system, encryption and codes embedded in the data,
to specific data algorithms. We review the merits and coverage of
the various methods of protection and compare that to the cyber
security industry standards.The question is: are we more
vulnerable using the CBTC system than the previous generation
distance-to-go systems?