Hardware Trojans are malicious design modifications, which pose severe threats to hardware security and trust. Since integrated circuit (IC) designs are difficult to modify after chip fabrication, it is of great importance to detect Trojans in the early design stage. In this work, we propose a novel hardware Trojan detection method at register transfer level (RTL) through semantic feature extraction and natural language processing (NLP). We convert the hardware design to control and data flow graph (CDFG) and develop a depth-first search and sliding window based algorithm for extracting and segmenting paths. This process preserves the structural and semantic features of RTL code. We then employ the NLP technique to perform Trojan detection at the granularity of RTL code statement. Specifically, we train the FastText model, which is proficient in word representation and text classification, to precisely pinpoint the Trojan-infected statements. We further integrate the word bigram features during the training process to improve the Trojan detection performance. Experimental evaluations using Trust-Hub benchmarks show that the proposed method can successfully pinpoint hardware Trojans with true positive rate (TPR), true negative rate (TNR), accuracy and F1-score of 97.77%, 99.95%, 98.86% and 97.46% respectively on average.

Consortium blockchain has been widely used in many application scenarios, where there is the demand for a universal user authentication and key exchange mechanism for all the application users in the system like Know Your Customer. Since current solutions heavily rely on traditional public-key cryptosystems that are vulnerable to attacks from quantum computers, we design and implement the first post-quantum (PQ) user authentication and key exchange system for consortium blockchain, which is integrated with all the PQ public-key (i.e., signature and encryption/KEM) algorithms in the current round of NIST call for national standard. Furthermore, we also provide chaincodes, related APIs together with client codes for further development. Last but not least, we perform a systematic evaluation on the performance of the system including the consumed time of chaincodes execution and the needed on-chain storage space. Based on the experiment results, we discuss the implications of our findings, which are helpful for the PQ blockchain-based application developers, the undergoing NIST call and the developers of the PQ algorithms.

Consortium blockchain has been widely used in different scenarios, where blockchain members demand that their uploaded data could be audited under their identities without exposing the data themselves. However, so far, no solution of privacy-preserving data auditing has been proposed. To address the problem, we propose zkrpChain, which focuses on protection of the integrity and privacy of the data uploaded by blockchain members while leaving their identities public. In zkrpChain, which is based on Hyperledger Fabric and Bulletproofs, both standard-range and arbitrary-range zero-knowledge range proofs generation and verification are supported. To improve the efficiency, the aggregation of multiple proofs and batch verification are also developed. For further development, we provide the client codes, chaincodes and related APIs. Finally, we conduct experiments to evaluate the performance of zkrpChaln, and the results show that the consumed time (in an 8-thread scheme) of chaincodes and needed on-chain space of zkrpChain are very close to Bulletproofs, which is evaluated in a single-machine environment.

In this study, the authors consider the problem of secure and reliable communication with uncertain channel state information (CSI) and present a new solution named active secure coding which combines the machine‐learning methods with the traditional physical‐layer secure coding scheme. First, the authors build a detectable wiretap channel model by combining the hidden Markov model with the compound wiretap channel model, in which the varying of channel block CSI is a Markov process and the detected information is a stochastic emission from the current CSI. Next, the authors present a CSI‐learning scheme to learn the CSI from the detected information by the Baum–Welch and Viterbi algorithms. Then the authors construct explicit secure polar codes based on the learned CSI, and combine it with the CSI‐learning scheme to form the active secure polar coding scheme. Simulation results show that an acceptable level of reliability and security can be achieved by the proposed active secure polar coding scheme.

In this study, the authors investigate the secure coding issue for a wiretap channel model with fixed main channel and varying wiretap channel, by assuming that legitimate parties can obtain the wiretapping channel state information (CSI) with some delay. For the symmetric degraded delay CSI case, they present an explicit weak security scheme by constructing secure polar codes on a one‐time pad chaining structure, and prove its weak security, reliability and capability of approaching the secrecy capacity for perfect CSI case with delay CSI assumption. Further for the symmetric no‐degraded delay CSI case, they present a modified multi‐block chaining structure in which the original subset of frozen bit is designed for conveying functional random bits securely. Then they combine this modified multi‐block chaining structure with the weak security scheme to construct an explicit strong security polar coding scheme, and prove its strong security, reliability and also the capability of approaching the secrecy capacity for perfect CSI case with delay CSI assumption. At last, they carry out simulations to prove the performance of both secure schemes.

The authors consider the problems of key exchange for one‐time pad along with the problem of rate sacrifice for secure polar coding over the two‐way wiretap channel under the strong security criterion. Based on existing techniques, they present a new hash chaining structure to solve the good bits sacrificing problem for achieving the strong security and constructed encryption embedded secure polar coding scheme for two‐way wiretap channel. To implement a one‐time pad without any key pre‐sharing, they design a secure and reliable transmission for both key and ciphertext coupling with the cooperative jamming strategy, which can also increase the secrecy rate for communication. As proved, extended upper bounds for both achievable secrecy rate pair and effective secrecy rate pair can be achieved under the strong security and reliability criterions.

A wiretap channel is an important model for wireless communication. By applying an extended multiblock polar coding scheme, recent literature has achieved the secrecy capacity of a general wiretap channel (not necessary degraded or symmetric). However, this secure polar coding scheme of physical layer also limits the transmission rate of the main channel, which may fail to meet the demand of high transmission rate and strong transmission security for practical wireless transmission. In order to obtain a higher secrecy transmission rate than the physical layer coding scheme over a general wiretap channel, a cross-layer encryption and coding scheme is proposed in this paper. In the proposed scheme, an onetime-pad encryption and a secure key transmission is constructed by combining a chaos stream cipher with the extended multiblock polar coding scheme. As proved, the proposed scheme has achieved a high secrecy transmission rate than the former physical layer coding scheme under the constraints of reliability and strong security for a general wiretap channel.