ZK-eSIM protects user privacy during eSIM profile provisioning
ZK-eSIM: A Privacy-Centric Zero-Knowledge Approach for eSIM Provisioning
Cryptography and Security
Summary
Current eSIM systems allow mobile operators to track devices and users when installing or updating eSIM profiles. This happens because stable device and profile identifiers are openly shared during the process. The authors propose ZK-eSIM, which uses special cryptographic proofs to hide these identifiers and keep each session separate and unlinked, preventing tracking. At the same time, their design allows authorized parties to trace users only when necessary through a strict approval process. They tested their system on real hardware and showed it works efficiently without big delays or changes to existing networks.
eSIMGSMA Remote SIM Provisioningdevice identifierszero-knowledge proofsubscriber anonymitysession unlinkabilityescrow mechanismcryptographic overheadJava Card applethonest-but-curious threat model
Authors
Liza Ahmad, Quan Shi, Joshua Haworth, Yilu Dong, Prosanta Gope, Behzad Abdolmaleki, Syed Rafiul Hussain
Abstract
GSMA Remote SIM Provisioning (RSP) enables over-the-air delivery of eSIM profiles, but it exposes long-lived identifiers during profile ordering and download. In particular, stable device identifiers (e.g., EID), profile identifiers, and long-lived certificate material enable mobile operators and profile-delivery infrastructure to link provisioning events to the same eUICC and, when combined with account records, to the same subscriber. This undermines subscriber anonymity and enables cross-session tracking. We present ZK-eSIM, a privacy-preserving redesign that achieves subscriber anonymity and provisioning-session unlinkability while retaining accountable traceability by exception. ZK-eSIM (i) replaces direct disclosure of device identifiers with a zero-knowledge proof of device validity and eligibility; (ii) enforces session unlinkability through short-lived, one-time pseudonymous credentials and per-session identifiers to prevent cross-session tracking; and (iii) provides privacy-preserving accountable traceability through a jointly authorised escrow mechanism, so that no single entity can unilaterally deanonymise a user. We formalise a multi-entity, honest-but-curious threat model and prove subscriber anonymity and the unlinkability of provisioning sessions under standard cryptographic assumptions. We implement a Java Card applet on a test eUICC to evaluate performance on commodity hardware with a modified LPA and SM-DP+ server. Our experiments quantify end-to-end cryptographic overhead relative to conventional RSP, confirming that ZK-eSIM adds only practical overhead, closing a critical privacy gap while preserving deployability within existing GSMA roles and interfaces.