Strongly Secure Communications Over the Two-Way Wiretap Channel

We consider the problem of secure communications over the two-way wiretap channel under a strong secrecy criterion. We improve existing results by developing an achievable region based on strategies that exploit both the interference at the eavesdropper's terminal and cooperation between legitimate users. We leverage the notion of channel resolvability for the multiple-access channel to analyze cooperative jamming and we show that the artificial noise created by cooperative jamming induces a source of common randomness that can be used for secret-key agreement. We illustrate the gain provided by this coding technique in the case of the Gaussian two-way wiretap channel, and we show significant improvements for some channel configurations.Comment: 11 pages, 7 figures, submitted to IEEE Transactions on Information Forensics and Security, Special Issue: "Using the Physical Layer for Securing the Next Generation of Communication Systems

Enhancing Secrecy with Multi-Antenna Transmission in Wireless Ad Hoc Networks

We study physical-layer security in wireless ad hoc networks and investigate two types of multi-antenna transmission schemes for providing secrecy enhancements. To establish secure transmission against malicious eavesdroppers, we consider the generation of artificial noise with either sectoring or beamforming. For both approaches, we provide a statistical characterization and tradeoff analysis of the outage performance of the legitimate communication and the eavesdropping links. We then investigate the networkwide secrecy throughput performance of both schemes in terms of the secrecy transmission capacity, and study the optimal power allocation between the information signal and the artificial noise. Our analysis indicates that, under transmit power optimization, the beamforming scheme outperforms the sectoring scheme, except for the case where the number of transmit antennas are sufficiently large. Our study also reveals some interesting differences between the optimal power allocation for the sectoring and beamforming schemes.Comment: to appear in IEEE Transactions on Information Forensics and Securit

Generic Construction of Dual-Server Public Key Authenticated Encryption with Keyword Search

Chen et al. (IEEE Transactions on Cloud Computing 2022) introduced dual-server public key authenticated encryption with keyword search (DS-PAEKS), and proposed a DS-PAEKS scheme under the decisional Diffie-Hellman assumption. In this paper, we propose a generic construction of DS-PAEKS from PAEKS, public key encryption, and signatures. By providing a concrete attack, we show that the DS-PAEKS scheme of Chen et al. is vulnerable. That is, the proposed generic construction yields the first DS-PAEKS schemes. Our attack with a slight modification works against the Chen et al. dual-server public key encryption with keyword search (DS-PEKS) scheme (IEEE Transactions on Information Forensics and Security 2016). Moreover, we demonstrate that the Tso et al. generic construction of DS-PEKS from public key encryption (IEEE Access 2020) is also vulnerable. We also analyze other pairing-free PAEKS schemes (Du et al., Wireless Communications and Mobile Computing 2022 and Lu and Li, IEEE Transactions on Mobile Computing 2022). Though we did not find any attack against these schemes, we show that at least their security proofs are wrong

Comments on "Dynamic Consensus Committee-Based for Secure Data Sharing With Authorized Multi-Receiver Searchable Encryption"

Recently, Yang et al. introduced an efficient searchable encryption scheme titled "Dynamic Consensus Committee-Based for Secure Data Sharing With Authorized Multi-Receiver Searchable Encryption (DCC-SE)," published in IEEE Transactions on Information Forensics and Security (DOI: 10.1109/TIFS.2023.3305183). According to the authors, DCC-SE meets various security requirements, especially the keyword trapdoor indistinguishability against chosen keyword attacks (KT-IND-CKA). In this letter, however, we reveal a significant vulnerability of DCC-SE: any users involved in the system can execute attacks against KT-IND-CKA security. This flaw potentially results in the unintended disclosure of sensitive keyword information related to the documents. We present a detailed cryptanalysis on DCC-SE. In addition, to address this vulnerability, we discuss the root cause and identify a flaw in the security proof of DCC-SE. Subsequently, we provide a solution that effectively addresses this concern without significantly increasing computational overhead.Comment: 2 page