Gene Multiple Sequence Alignment is crucial for genomic data analysis, forming the basis for studying its biological significance. The digitization of genomic data allows collaborative analysis on cloud platforms, improving the efficiency and precision of genomic research. However, gene sequences contain sensitive information, posing a risk of privacy leakage with unauthorized access. Balancing privacy, accuracy, and efficiency in multiple sequence alignment for long gene sequences remains a challenge. In this paper, we propose a distributed privacy-preserving multiple sequence alignment scheme for long sequences based on secure multi-party computation. Our scheme includes a method for segmenting long sequences to achieve partially distributed computing and a privacy-preserving method for calculating edit distance among subsequences using secret sharing. The scheme consists of a distributed computing phase and an aggregate computing phase, optimizing efficiency by dropping repeated subsequences alignment. Our proposed scheme achieves accurate and efficient privacy-preserving alignment for long gene sequences.

Internet of Medical Things (IoMT) has garnered significant research attention from both academic and medical institutions. However, the sensitive medical data involved in IoMT raises security and privacy concerns. To mitigate these, ring signature has surfaced as a proper solution, which offers unforgeability and anonymity. Unfortunately, most multi-signer ring signature schemes require a predetermined number of signers and are difficult to adjust dynamically. Additionally, traditional ring signatures have limited adaptability for IoMT due to their reliance on a single entity. It is challenging to effectively define different signature permissions for users of various entities, such as patients and doctors. Therefore, research focusing on constructing a dynamic multi-signer ring signature for multi-party participation remains a critical and ongoing challenge. In this paper, we present ASMR, an anonymity-enhanced sequential multi-signer ring signature scheme for secure medical data sharing in IoMT. ASMR contains two different rings, PR and DR, for patients and doctors, respectively. It allows patients in PR to anonymously sign their electronic healthcare record (EHR) owned by doctors in DR, overcoming the reliance on a single entity in existing approaches while enhancing the anonymity of the signature. Meanwhile, ASMR introduces the concept of signature chaining, allowing multiple users in DR to co-sign information in sequence. In addition, it ensures that each generated signature is traceable, offering a transparent system. We also formally prove the security of ASMR in the random oracle model. Comprehensive performance evaluations indicate that ASMR excels in both computational and storage overhead. In the best case, computational overhead is reduced by approximately 4.7×-61.7×, while storage overhead is reduced by approximately 26.7×-212.8× compared to prior arts.

A smart grid is a large-scale cyber-physical fusion system where the physical layer and the cyber layer are interdependent. Attackers only need to invade the cyber layer, relying on its control function and cascading failures, to paralyze the smart grid. To analyze the real interaction between adversaries in the smart grid, we propose a new multistage adversarial game model that protects smart grid against cyber-physical attacks. Attackers can destroy the regional control center of the cyber layer, whereas defenders can strengthen the physical layer nodes. The solution of such game is based on the Minimax-Q algorithm. Both attackers and defenders can actively participate in the game and maximize their minimum rewards in this multistage game. Cascading failures and optimal load shedding are utilized to design the reward function. We apply this model to IEEE 39-bus system and compare it with a nonadversarial game. When defenders are passive players, the load loss is 52.48${\mathrm{{\% }}}$after two actions by the attacker. When defenders are active players, it takes at least four pairs of confrontation actions to inflict a 50${\mathrm{{\% }}}$load loss. The results show that attacks on the cyber layer are more destructive and also give rise to various defense strategies.

With the emergence of fifth-generation (5G) technology, the air-to-ground (ATG) communication system based on 5G public mobile communication technology makes it possible to provide data services for in-flight communication. Customer premises equipment (CPE) is connected to ATG base stations to provide network access for user devices in-cabin. However, the handover authentication performed by CPEs during a handover between ATG base stations poses security risks and incurs a lot of overhead. Furthermore, frequent handovers between base stations and the limited computational resources of the CPE make the protection of security properties even more challenging. In this paper, we propose a lightweight group pre-handover authentication scheme for aviation 5G ATG networks. By leveraging the predictability of flight paths, all CPEs on the same aircraft can complete handover authentication before arriving at the next base station, and handover authentication delay can be ignored, providing seamless communication services for user devices in the cabin. The scheme utilizes the extended Chebyshev chaotic map and symmetric encryption technology to reduce computational overhead and adapt to the limited computing resources of CPE. Security and performance analysis show that our scheme achieves lightweight and efficiency while ensuring security performance and outperforms other relevant schemes.

With the development of bioinformatics technology, there is an increasing demand for gene sequence alignment. Gene sequence alignment can determine the homology between sequences and plays an increasingly prominent role in the traceback of species, the construction of phylogenetic trees and the diagnosis of human diseases. So far, gene sequence alignment schemes usually do not consider the privacy of participants, which could cause the disclosure of sensitive information, thus there is an urgent need for secure gene sequence alignment schemes. In this paper, we model genomic data from the perspective of privacy protection. On this basis, we design a scheme of gene sequence alignment for the analysis of homologous genopathy. Genopathy private query is realized by adding redundant query conditions, and secure gene sequence alignment is realized by using garbled circuit. And we propose merging truth table to implement a garbled equality gate circuit that only needs to send ciphertext once. The times of encryption and decryption reduced to a third of the general garbled equality gate circuit. Consequently, the scheme can protect the data privacy, query privacy and output privacy of both participants and has better practicability.

SCADA systems are one of the critical infrastructures and face many security threats. Attackers can control SCADA systems through network attacks, destroying the normal operation of the power system. It is important to conduct a risk assessment of security threats on SCADA systems. However, existing models for risk assessment using attack trees mainly focus on describing possible intrusions rather than the interaction between threats and defenses. In this paper, we comprehensively consider intrusion likelihood and defense capability and propose a quantitative risk assessment model of security threats based on attack countermeasure tree (ACT). Each leaf node in ACT contains two attributes: exploitable vulnerabilities and defense countermeasures. An attack scenario can be constructed by means of traversing the leaf nodes. We set up six indicators to evaluate the impact of security threats in attack scenarios according to NISTIR 7628 standard. Experimental results show the attack probability of security threats and high-risk attack scenarios in SCADA systems. We can improve defense countermeasures to protect against security threats corresponding to high-risk scenarios. In addition, the model can continually update risk assessments based on the implementation of the system’s defensive countermeasures.

Aircraft Communications Addressing and Reporting System (ACARS) has been widely used in aviation datalink. However, for lack of security designs, ACARS faces increasing security threats such as eavesdropping and message injection. Although several security solutions has been proposed on aviation surveillance message, such as Automatic Dependent Surveillance-Broadcast, those on ACARS have received far less attention. To further improve the session security and privacy of civil aviation users, we put forwards a compatible protocol for ACARS datalink to protect message security as well as aircraft identity privacy. The proposed solution provides communication confidentiality, and supports data integrity and user identity verification. Meanwhile, by replacing the aircraft’s identity transmitted in plaintext with a variable anonymity, the privacy of an aircraft is protected from the disclosure of aircraft identity. Moreover, our protocol is compatible with current ACARS standards, making the proposed solution easy-to-deploy and practical. Formal analysis and simulations are carried out to make sure the security of proposed protocol.

Identity-based remote data auditing schemes can verify data integrity and provide a simple identity authentication and management for multiple users. However, prior works on identity-based remote data auditing lack the support of dynamic operations. In these schemes, tag generation is linked to the index of data block, which is related to update operations such as modification, insertion and deletion. If users perform dynamic operations on a data block, the tags of all subsequent blocks need to be modified. It means that if users want to update data on a big data platform, they have to download the whole file, update the file and send the updated file to the big data platform. Such pattern will bring huge communication overhead. In this paper, we propose an identity-based dynamic data auditing scheme which supports dynamic data operations, including modification, insertion and deletion. As far as we know, there is still no other identity-based data auditing scheme that supports dynamic operations. In particular, to achieve efficient dynamic operations, we use the data structure of Merkle hash tree for block tag authentication, which helps update data with integrity assurance. Analyses of security and performance show that the proposed scheme is efficient and secure.

Orbital angular momentum (OAM) has the characteristics of high dimension and rotational symmetry. Quantum key distribution (QKD) schemes using OAM can carry more quantum information, improve the transmission capacity of information and reduce the errors caused by reference frame calibration errors. In this paper, we propose a measurement-device-independent QKD scheme based on OAM with dual detectors. On the basis of the measurement-device-independent QKD protocol, we use OAMs to encode the key information and then send them to a third-party measurement device. In the process of measurement, we adopt the dual-detector theory to improve key generation rate and transmission distance. Simulation analyses show that the secure transmission distance of our scheme can reach 140 km, which is about 30km more than the scheme using single detector.

Homomorphic encryption enables computation on encrypted data while maintaining secrecy. This leads to an important open question whether quantum computation can be delegated and verified in a non-interactive manner or not. In this paper, we affirmatively answer this question by constructing the quantum homomorphic encryption scheme with quantum obfuscation. It takes advantage of the interchangeability of the unitary operator, and exchanges the evaluation operator and the encryption operator by means of equivalent multiplication to complete homomorphic encryption. The correctness of the proposed scheme is proved theoretically. The evaluator does not know the decryption key and does not require a regular interaction with a user. Because of key transmission after quantum obfuscation, the encrypting party and the decrypting party can be different users. The output state has the property of complete mixture, which guarantees the scheme security. Moreover, the security level of the quantum homomorphic encryption scheme depends on quantum obfuscation and encryption operators.