Improving Air Interface User Privacy in Mobile Telephony (original) (raw)

Improving security and privacy in current mobile systems

2017

As has been widely discussed, the GSM system only offers unilateral authentication of the mobile phone to the network; this limitation permits a range of attacks. While adding support for mutual authentication would be highly beneficial, changing the way GSM serving networks operate is not practical. The 3G and 4G mobile systems rectify the GSM weakness by providing mutual authentication between phone and network, and significantly improve their security properties by comparison with 2G (GSM). However, significant shortcomings remain with respect to user privacy, most notably the decades-old privacy problem of disclosure of the permanent subscriber identity (IMSI), a problem arising in all generations of mobile networks and that makes IMSI catchers a real threat. Although a number of possible modifications to 2G, 3G and 4G protocols have been proposed designed to provide greater user privacy, they all require significant alterations to the existing deployed infrastructures, which ar...

Privacy of User Identities in Cellular Networks

Helsingin yliopisto, 2021

This thesis looks into two privacy threats of cellular networks. For their operations, these networks have to deal with unique permanent user identities called International Mobile Subscriber Identity (IMSI). One of the privacy threats is posed by a device called IMSI catcher. An IMSI catcher can exploit various vulnerabilities. Some of these vulnerabilities are easier to exploit than others. This thesis looks into fixing the most easily exploitable vulnerability, which is in the procedure of identifying the subscriber. This vulnerability exists in all generations of cellular networks prior to 5G. The thesis discusses solutions to fix the vulnerability in several different contexts.

Enhancing end-users privacy in 3G networks

2003

Mobile/wireless Internet is becoming available with the advent of third generation (3G) mobile communication systems. Along with the variety of new perspectives, mobile Internet also raises new concerns on security issues. The radio transmission is by nature more susceptible to eavesdropping and fraud in use than wireline transmission. The user mobility and the universal network access certainly provoke security treats. The introduction of IP-based transport technology to the core of 3G networks brings along new vulnerabilities and potential threats. Mobile network operators do not deploy their own private networks, but they rather rely on the existing Internet infrastructure for the establishment of intra-network, and inter-network communications. Furthermore, the complex network topologies and the heterogeneity of the involved technologies increase the dependability challenge.

Identity management in mobile cellular networks and related applications

Information Security Technical Report, 2004

While identity management systems for the Internet are debated intensively identity management in mobile application has grown silently over the last 12 years. More then 980 million GSM subscriptions and the SIM infrastructure are the basis for many application oriented initiatives to manage identities. This paper discusses the technological foundations as well as the application scenarios and the privacy challenges and opportunities.

Protecting IMSI and User Privacy in 5G Networks

Proceedings of the 9th EAI International Conference on Mobile Multimedia Communications, 2016

In recent years, many cases of compromising users' privacy in telecom networks have been reported. Stories of "fake" base stations capable of tracking users and collecting their personal data without users' knowledge have emerged. The current way of protecting privacy does not provide any protection against an active attacker on the air-interface, claiming to be a legitimate network that has lost the temporary identity. Moreover, there is also no protection against passive eavesdroppers who are present when requests for International Mobile Subscriber Identity (IMSI) are made. This paper presents a new method for protecting the IMSI by means of establishing a pseudonym between the user equipment and the home network. The pseudonym is derived locally at the user equipment and the home network without affecting existing Universal Subscriber Identity Modules (USIMs). We analyse the solution from a technical perspective, as well as from a regulatory and operational perspective. The presented method protects the IMSI from passive and active IMSI-catchers as well as honest but curious serving networks. Moreover, it can recover from lock-out situations where one party has lost the pseudonym.

Enhanced Identity Privacy in UMTS

International Journal of Ad Hoc and Ubiquitous Computing, 2016

Subscriber's identity privacy in mobile networks has been an exciting research area. Earlier, researchers were focused on protecting it over the radio link between the mobile device and the serving network. Whereas now, they are considering the need for protecting the same from the serving network itself, due to the security and flexibility that it promises to bring into roaming situations. Towards this, numerous protocols have been proposed for mobile networks in general. However, in universal mobile telecommunications system (UMTS), one of the most widely deployed mobile networks, not much research has been conducted in this direction. In this paper, we make an effort to fill in this gap by proposing an extension that can be easily adapted in UMTS. We also establish the security, robustness and correctness of this extension through statistical, security and formal analysis.

Another Look at Privacy Threats in 3G Mobile Telephony

Lecture Notes in Computer Science, 2014

Arapinis et al. [1] have recently proposed modifications to the operation of 3G mobile phone security in order to address newly identified threats to user privacy. In this paper we critically examine these modifications. This analysis reveals that the proposed modifications are impractical in a variety of ways; not only are there security and implementation issues, but the necessary changes to the operation of the system are very significant and much greater than is envisaged. In fact, some of the privacy issues appear almost impossible to address without a complete redesign of the security system. The shortcomings of the proposed 'fixes' exist despite the fact that the modifications have been verified using a logic-based modeling tool, suggesting that such tools need to be used with great care.

Obscuring Users’ Identity in VoIP/IMS Environments

Computers & Security, 2014

Next Generation Networks bring together wired and wireless architectures, under the umbrella of an all IP architecture. Architectures such as the IP Multimedia Subsystem (IMS) offer advanced services at very low cost but also inherit IP infrastructure's security and privacy issues. The utilized signalling protocol (i.e. Session Initiation Protocol) and the related specifications are both overlooking users' privacy, leaving public and private identities unprotected to eavesdroppers. Existing solutions require either the existence of a public key infrastructure or the establishment of the appropriate mechanism for managing symmetric keys. We propose a novel one-time identity mechanism for obscuring users' real identity against eavesdroppers. The solution exploits the advantages of commutative functions, enabling the communicating parties to exchange data without pre-established keys nor any modification in the infrastructure. All participating entities generate one-time random identities providing in this way unlinkability and anonymity services as well. We evaluate the proposed mechanism through an open source IMS platform. Results have provided evidence that the client's response times are not considerably affected by the proposed mechanism, while the overhead imposed to the IMS core is negligible.