184	Bluetooth Security

Client	Server
	Security filter
M	Check if
	access is	Access control
	granted?
Response	If OK, forward	database
	M to SIM
	M
	SIM

Figure 10.7 Access control to a SIM.

process or a security filter will check all messages from the client to the subscription module, as is illustrated in Figure 10.7. The filter makes sure that only messages allowed according to the access database are forwarded to the subscription module.

Another security problem with the SIM access profile is that the PIN needed to open the SIM is sent from the client to the server. This means that if the client device is untrusted or infected by malicious software, the PIN for the card can be intercepted by a third party. To avoid this, the access filter in Figure 10.7 shall not accept PIN commands from the client, but demand the SIM to be opened from the server device. Then the user must enter the SIM PIN into the trusted server device before the SIM access profile connection is set up. Clearly, this implies that a proper input interface must be present at the SIM access server.

References

[1]Bluetooth Special Interest Group, Bluetooth Security White Paper, Version 1.0, 19 April 2002.

[2]Gehrmann, C., and K. Nyberg, “Enhancements to Bluetooth Baseband Security,” Proc. Nordsec 2001, Copenhagen, November 2001, pp. 39–53.

[3]Bluetooth Special Interest Group, Specification of the Bluetooth System, Version 1.1, Profiles, Part K:6 Headset Profile, February 2001.

[4]Bluetooth Special Interest Group, Specification of the Bluetooth System, Version 1.0, Personal Area Networking Profile, February 2003.

[5]Bluetooth Special Interest Group, Specification of the Bluetooth System, Version 1.0, Bluetooth Network Encapsulation Protocol (BNEP) Specification, February 2003.

Security for Bluetooth Applications	185

[6]IEEE, IEEE Std., 802.1x-2001, Version 2001, Port-Based Network Access Control, June 2001.

[7]Dierks, T., and C. Allen, The TLS Protocol, Version 1.0, RFC 2246, January 1999.

[8]Kent, S., and R. Atkinson, IP Encapsulating Security Payload (ESP), RFC 1827, November 1998.

[9]3rd Generation Partnership Programme, 3GPP TS 11.11, Specification of the Subscriber Identity Module Mobile Equipment (SIM-ME) Interface, Version 8.10.0, September 2003.

[10]International Organization for Standardization, ISO/IEC 7816-3 Information Technol- ogy—Identification Cards Integrated Circuit(s) Cards with Contacts—Part 3: Electronic Signals and Transmission Protocols, 2nd ed., 1997.

[11]Bluetooth Special Interest Group, Specification of the Bluetooth System, Version 0.95, SIM Access Profile Specification, June 2002.