Closing the HNDL Window in Consumer eSIM Provisioning: Hybrid Post-Quantum Migration, Formal Verification, and...

Area of Science:

• Cryptography and Network Security
• Embedded Systems Security
• Quantum Computing Impact

Background:

• Embedded Subscriber Identity Modules (eSIMs) use GSMA SGP.22 for remote SIM provisioning (RSP).
• RSP relies on classical cryptography, posing a Harvest-Now-Decrypt-Later (HNDL) risk to long-lived eSIM profiles.
• Transport Layer Security (TLS) upgrades alone are insufficient due to key exchange occurring below the transport layer.

Purpose of the Study:

• To develop a systematic post-quantum cryptography (PQC) migration framework for consumer RSP.
• To analyze PQC configurations for SGP.22 key agreement against quantum adversaries.
• To identify resource constraints for PQC deployment on eSIMs.

Main Methods:

• Modeling four SGP.22 on-card key-agreement configurations.
• Symbolic verification using ProVerif.
• Device-grounded evaluation using an eUICC and PQC measurements on an ARM Cortex-M4F core.

Main Results:

• Hybrid classical and PQC key exchange is the minimal configuration resisting HNDL.
• Fully PQC configurations offer additional protection against signature forgery.
• Volatile Random Access Memory (RAM) is identified as the primary deployment constraint, not computation.

Conclusions:

• A hybrid PQC approach is necessary for HNDL resistance in consumer RSP.
• Future PQC migration must consider memory constraints on embedded devices.
• A capability-negotiation mechanism is proposed to match configurations to available card memory.