Third-generation (3G) mobile systems provide enhanced
security by deploying a mobile terminal
to Universal Mobile Telecommunications System
(UMTS) Terrestrial Radio Access Network
(UTRAN) mutual authentication and by addressing the
vulnerabilities in 2G’s underlying cryptographic technology.
1 Such systems also pay special attention to user privacy
by deploying an identity management scheme to
protect the confidentiality of user identity, position, and
service delivery.2
With these features in mind, 3G mobile subscribers
might feel more secure when connecting to 3G networks,
but this perception doesn’t reflect reality when
you consider all the elements in the service provision
path, including the core network. The 3G core network
consists of the circuit-switched (CS) domain, the
packet-switched (PS) domain, and the Internet Protocol
(IP) multimedia subsystem (IMS).3 The CS domain
handles traffic switching and signaling for voice
communications, linking the UTRAN with other
voice networks. The PS domain handles traffic switching
and signaling for data communications, linking the
UTRAN with other packet domain networks (PDNs)
such as the Internet; the IMS is a complementary subsystem
that provides multimedia services over the PS
domain. This article focuses on the open security issues
in the PS domain—in particular, how honeynet
technology can be a cost-effective solution that increases
security.
Core network security
In recent years, mobile telecommunication networks
have transformed from infrastructures that provided
voice and limited
data services to infrastructures
that offer a wide range of multimedia options.
4 The new demands on service provisions require
improved versions of supporting systems for charging
and billing, roaming, and addressing, as well as the necessary
security services for protecting the confidentiality,
integrity, and availability of all types of information, including
user traffic, signaling, and control data.5
The outcome of this transformation was an upgrade
from the existing closed Signaling System 7-based networks
to IP-based systems that combine several old and
new technologies and applications under the pressure of
timely service delivery startup. Several research studies
report the security vulnerabilities that have subsequently
arisen:6–10
• a lack of intrusion detection systems (IDSs);
• inadequate firewall architectures;
• no security layers; and
• uncontrolled communication with roaming partners.
Such vulnerabilities ultimately lead to threats, which fall
into these categories:
• billing attacks via gateway filters;
• exposure of critical production systems that implement
packet switching—such as gateway general packet
radio service (GPRS) support nodes (GGSNs) and
serving GPRS support nodes (SGSNs)—to attacks;


Download full report
http://selab.iecs.fcu.edu.tw/course/96/d...lass_4.pdf