The IMSI Pseudonymization project will design a specification and provide a reference implementation of a mechanism to conceal the IMSI (international mobile subscriber identity) of a mobile subscriber on the radio interface. The IMSI is used to uniquely identify each subscriber in a (2G, 3G, 4G, 5G) cellular network. However, the privacy of users is not really well protected: current specification require to transfer the IMSI in plain-text at various times before an encrypted connection can be set up. The present project will specify, implement and evaluate a method by which the IMSI will be concealed on the air interface with no modifications to existing mobile phones or any network elements of the operator beyond the HLR/HSS (which implements the authentication on the network side).
This project is funded by NLnet and the NGI0 PET Fund.
- Create draft specification (completed, see imsi-pseudo-spec.pdf)
- Implement in Osmocom <-- we're here
- Update specification with experience from implementation
- Submit proposal for optional IMSI pseudonymization into the 3GPP standardization process