B2B Integration : A Practical Guide to Collaborative E-commerce

Wireless Technologies 355
Most of the state-of-the-art IS-95 CDMA and IS-136 TDMA terminals
support roaming to the analog first generation AMPS system (dual
mode terminals). This is currently a major problem for the IS-95
CDMA and IS-136 TDMA operators as it also expands the AMPS
system's lack of security to the 2G systems.
GSM-based mobile systems provide mobile user authentication and
security over the radio interface as an integrated part of the system. The
GSM security is based on the trust between network operators and on a
shared secret key (Ki) stored on the user-subscriber's identification
module (SIM) and in the Authentication Center (AUC) of the operator.
Third generation systems
The third generation mobile systems (3G) will be available soon after
the year 2002. The security of first and second-generation systems
is based on the traditional telecom security model (separation of user
data and signaling data). The third generation mobile systems will be
IP-based and, at least partially, connected to the Internet. IP-networks
are 'open networks', which do not separate signaling from the user
data. This allows malicious users to exploit the faults of the protocol
stacks to gain access to data or network resources. The 3G systems
have to adopt a new security policy and build an Internet-like security
architecture (firewalls, virtual private networking, end-to-end encryption,
etc.).
12.4.2. Security issues in WAP
WAP allows the introduction of hypertext services to mobile systems.
The services are stored on servers in the network and they are used
with a browser program from the mobile terminal. Both the operator's
network and the service provider's WAP servers can be connected to
the public Internet, thus exposing the WAP stack and servers to attacks.
The main areas where security should be addressed are:
• Security between the mobile phone and the antenna;
• Security between the antenna and the WAP gateway; and
• Security between WAP gateway and origin server.