The 5G-AKA protocol, defined by 3GPP for authentication and key agreement in 5G networks, remains vulnerable to linkability, synchronization failure, and Sequence Number (SQN) exposure attacks. These issues threaten user privacy and service availability. Existing improvements often retain these flaws or cause high overhead due to continued use of the legacy SQN mechanism from 3G. In this paper, we propose 5G-RNAKA, a secure and efficient AKA protocol for 5G systems. Unlike 5G-AKA, 5G-RNAKA eliminates SQN counters and instead utilizes random numbers generated by the Universal Subscriber Identity Module (USIM) in 5G User Equipment (UE) for session identification. This random number is embedded in the reply message from the service network (SN) to prevent replay attacks against the UE. Additionally, by removing the SQN mechanism, 5G-RNAKA enhances user privacy by preventing attackers from linking challenge-response sessions. It also enables the UE to authenticate the SN, effectively mitigating the risk of SN impersonation. We formally verify that 5G-RNAKA achieves its security goals of privacy, authentication, and secrecy using the state-of-the-art formal verification tool, Tamarin Prover. Our implementation and evaluation further demonstrate that 5G-RNAKA improves communication efficiency and reduces storage overhead. While primarily designed for 5G, 5G-RNAKA's features align with emerging trends in 6G authentication, suggesting its potential for adaptation to future 6G architectures.

The FIDO protocol suite aims at allowing users to log in to remote services with a local and trusted authenticator. With FIDO, relying services do not need to store user-chosen secrets or their hashes, which eliminates a major attack surface for e-business. Given its increasing popularity, it is imperative to formally analyze whether the security promises of FIDO hold. In this paper, we present a comprehensive and formal verification of the FIDO UAF protocol by formalizing its security assumptions and goals and modeling the protocol under different scenarios in ProVerif. Our analysis identifies the minimal security assumptions required for each of the security goals of FIDO UAF to hold. We confirm previously manually discovered vulnerabilities in an automated way and disclose several new attacks. Guided by the formal verification results, we also discovered two practical attacks on two popular Android FIDO apps, which we responsibly disclosed to the vendors. In addition, we offer several concrete recommendations to fix the identified problems and weaknesses in the protocol.

Gene regulatory networks (GRNs)are involved in various biological processes, such as cell cycle, differentiation and apoptosis. The existing large amount of expression data, especially the time-series expression data, provide a chance to infer GRNs by computational methods. These data can reveal the dynamics of gene expression and imply the regulatory relationships among genes. However, identify the indirect regulatory links is still a big challenge as most studies treat time points as independent observations, while ignoring the influences of time delays. In this study, we propose a GRN inference method based on information-theory measure, called NIMCE. NIMCE incorporates the transfer entropy to measure the regulatory links between each pair of genes, then applies the causation entropy to filter indirect relationships. In addition, NIMCE applies multi time delays to identify indirect regulatory relationships from candidate genes. Experiments on simulated and colorectal cancer data show NIMCE outperforms than other competing methods. All data and codes used in this study are publicly available at https://github.com/CSUBioGroup/NIMCE.

We present a novel attack named “Authenticator Rebinding Attack,” which aims at the Fast IDentity Online (FIDO) Universal Authentication Framework (UAF) protocol implemented on mobile devices. The presented Authenticator Rebinding Attack rebinds the victim’s identity to the attacker’s authenticator rather than the victim’s authenticator being verified by the service in the UAF protocol, allowing the attacker to bypass the UAF protocol local authentication mechanism by imitating the victim to perform sensitive operations such as transfer and payment. The lack of effective authentication between entities in the implementations of the UAF protocol used in the actual system causes the vulnerability to the Authenticator Rebinding Attack. In this paper, we implement this attack on the Android platform and evaluate its implementability, where results show that the proposed attack is implementable in the actual system and Android applications using the UAF protocol are prone to such attack. We also discuss the possible countermeasures against the threats posed by Authenticator Rebinding Attack for different stakeholders implementing UAF on the Android platform.

VBTC (vehicle‐to‐vehicle communication based train control) has gradually become an important research trend in the field of rail transit. This has resulted in advantages of decreasing the number of pieces of wayside equipment and improving the efficiency of real‐time system communication. Characteristics and mechanism of train‐to‐train communication, as key implementation technology of safety critical system, are given and discussed. A new method, based on the LTS (labelled transition system) model checking, is proposed for verifying the safety properties in the communication procedure. The LTS method is adapted to model system behaviours; analysis and safety verification are checked by means of LTSA (labelled transition system analyzer) software. The results show that it is an efficient method to verify safety properties, as well as to assist the complex system’s design and development.