To protect mobile phone from tracking by third parties, mobile telephony systems rely on periodically changing pseudonyms. We experimentally and formally analyse the mechanism adopted to update these pseudonyms and point out design and implementation weaknesses that defeat its purpose by allowing the identification and/or tracking of mobile telephony users. In particular, the experiments show that the pseudonym changing mechanism as implemented by real networks does not achieve the intended privacy goals. Moreover, we found out that the standard is flawed and that it is possible to exploit the procedure used to assign a new pseudonym, the TMSI reallocation procedure, in order to track users. We propose countermeasures to tackle the exposed vulnerabilities and formally prove that the 3GPP standard should require the establishment of a fresh ciphering key before each execution of the TMSI reallocation procedure to provide unlinkability.
|Title of host publication||21st Annual Network and Distributed System Security Symposium (NDSS'14)|
|Publisher||The Internet Society|
|Number of pages||14|
|Publication status||Published - 22 Feb 2014|
|Event||2014 Network and Distributed System Security Symposium - San Diego, United States|
Duration: 23 Feb 2014 → 26 Feb 2014
|Symposium||2014 Network and Distributed System Security Symposium|
|Abbreviated title||NDSS 2014|
|Period||23/02/14 → 26/02/14|
FingerprintDive into the research topics of 'Privacy through Pseudonymity in Mobile Telephony Systems'. Together they form a unique fingerprint.
- School of Informatics - Reader
- Laboratory for Foundations of Computer Science
- Foundations of Computation
Person: Academic: Research Active