Post-Quantum Key Exchange and ID Encryption Analyses for 5G Mobile Networking
Qaiser Khan, Sourav Purification, Sang‐Yoon Chang · 2025
5G technology addresses user privacy concerns in cellular networking by encrypting subscriber identifier with ellip-tic curve-based encryption and then transmitting it as ciphertext known as Subscriber Concealed Identifier (SUCI). However, an adversary equipped with a quantum computer can break a discrete logarithm-based elliptic curve algorithm and the user privacy in 5G is at stake against quantum attacks. In this paper, we study the incorporation of the post-quantum ciphers in the SUCI calculation both at the user equipment and at the core network, which involves the shared key exchange and then using the resulting key for the ID encryption. We experiment on different hardware platforms to analyze the PQC key exchange and encryption using NIST-standardized CRYSTALS-Kyber. Our analyses focus on the performances and compare the Kyber-based key exchange and encryption with the current (pre-quantum) Elliptic-curve Diffie-Hellman (ECDH). The performance analyses are critical because mobile networking involves resource-limited and battery-operating mobile devices. We measure and analyze not only the time and CPU-processing performances but also the energy and power performances. Our results show that Kyber-512 is the most efficient and even has better performance (i.e., faster computations, and lower energy consumption) than ECDH.