Imtiaz Karim

5G transmits System Information Blocks (SIBs) without authentication during bootstrapping, enabling fake base station attacks. Direct NIST-PQC integration is infeasible: ML-DSA requires 34 fragmented packets and up to 5,282 ms delay. We present a two-phase PQ migration framework. Phase I provides transitional security via hierarchical identity-based threshold signatures with a fail-stop mechanism backed by PQ-secure audit logging. This transitional solution requires only 144 B overhead and 2.99 ms end-to-end delay, which is three orders of magnitude faster than ML-DSA. Phase II achieves full PQ authentication via a TESLA-style HMAC chain anchored by a compact post-quantum signature, which is applied once per epoch (160.07 ms delay). Both phases fit within 1-2 SIB1 packets and are validated on a real over-the-air 5G testbed.

5G and beyond cellular systems embrace the disaggregation of Radio Access Network (RAN) components, exemplified by the evolution of the fronthaul (FH) connection between cellular baseband and radio unit equipment. Crucially, synchronization over the FH is pivotal for reliable 5G services. In recent years, there has been a push to move these links to an Ethernet-based packet network topology, leveraging existing standards and ongoing research for Time-Sensitive Networking (TSN). However, TSN standards, such as Precision Time Protocol (PTP), focus on performance with little to no concern for security. This increases the exposure of the open FH to security risks. Attacks targeting synchronization mechanisms pose significant threats, potentially disrupting 5G networks and impairing connectivity. In this article, we demonstrate the impact of successful spoofing and replay attacks against PTP synchronization. We show how a spoofing attack is able to cause a production-ready O-RAN and 5G-compliant private cellular base station to catastrophically fail within 2 seconds of the attack, necessitating manual intervention to restore full network operations. To counter this, we design a Machine Learning (ML)-based monitoring solution capable of detecting various malicious attacks with over 97.5% accuracy.

The IEEE 802.11 family of standards, better known as WiFi, is a widely used protocol utilized by billions of users. Previous works on WiFi formal verification have mostly focused on the four-way handshake and other security aspects. However, recent works have uncovered severe vulnerabilities in functional aspects of WiFi, which can cause information leakage for billions of devices. No formal analysis method exists able to reason on the functional aspects of the WiFi protocol. In this paper, we take the first steps in addressing this gap and present an extensive formal analysis of the functional aspects of the WiFi protocol, more specifically, the fragmentation and the power-save-mode process. To achieve this, we design a novel segment-based formal verification process and introduce a practical threat model (i.e., MAC spoofing) in Tamarin to reason about the various capabilities of the attacker. To this end, we verify 68 properties extracted from WiFi protocol specification, find 3 vulnerabilities from the verification, verify 3 known attacks, and discover 2 new issues. These vulnerabilities and issues affect 14 commercial devices out of 17 tested cases, showing the prevalence and impact of the issues. Apart from this, we show that the proposed countermeasures indeed are sufficient to address the issues. We hope our results and analysis will help vendors adopt the countermeasures and motivate further research into the verification of the functional aspects of the WiFi protocol.