The maximum likelihood attack strategy is known to be the optimal attack strategy for an eavesdropper in a wiretap channel scenario with additive white Gaussian noise channels under the distinguishing security criterion. The main drawback of this optimal attack is its high computational complexity. While this complexity doesn’t hinder the eavesdropper since he has unlimited computing power, it does present a significant challenge for legitimate parties. For them, it is extremely difficult, if not impossible, to estimate the outcome of the optimal attacker strategy to validate the secrecy of their communication system. In this paper, we introduce a low complexity method for generating upper and lower bounds on the attack performance of the eavesdropper to validate the security against the maximum likelihood attack strategy. We theoretically establish that the derived bounds represent valid constraints on the attack success probability under suitable constraints. The validation method is based on list generation and can be used for any linear block code. Furthermore, we propose a list generation algorithm for this validation method and show different ways to further reduce the complexity. We compare the proposed validation method with state-of-the-art attack strategies in numerical simulations for various error-correcting codes.

In this study, we examine different functions for the security layer of a seeded modular coding scheme for semantic security. We investigated the separation of the seed set into dispersing and non-dispersing seeds. The separation exists for all five implemented security functions in combination with all three tested error correcting codes. We show a simple procedure to reduce the probability of dispersing seeds for all security functions in two of three error correcting codes. Additionally, it was shown that Eve has an advantage in extracting information from her channel output if dispersing seeds are used. The simulations showed that this advantage can lead in special cases to a better information extraction despite larger encoding randomness. To the best of the authors’ knowledge, this is the first analytic comparison of different security functions for a seeded modular coding scheme of this kind.

This paper proposes a system architecture that embeds semantically-secure information-theoretic physical layer security (IT-PLS) non-intrusively into a 5G New Radio (NR) system in order to protect uplink transmissions via physical uplink control channels (PUCCH) against post-quantum eaves-dropping attacks. We implement a proof of concept of such system employing a code construction based on a modular coding scheme with a universal hash function that ensures semantic secrecy. We conduct link-level simulations of wiretap channels under different frequency-selective fading conditions and noise characteristics in order to evaluate the performance of such implementation for slow and fast fading scenarios. We model them using tapped delay line channel models involving rural and urban scenarios with line-of-sight (LOS) and non-LOS radio conditions, as specified by the 3GPP TR 38.901. We characterize such system by measuring the distinguishing error rate, block error rate, and secrecy outage probability under different time-varying fading channels. Our case study outlines how IT-PLS can be transparently embedded into future 6G systems as well.

This paper compares different algorithms to check semantic security on AWGN wiretap channels. Each algorithm provides upper and lower bounds on the performance of an attack strategy that is close to the best attack strategy. The advantage of these algorithms is that they have lower computational complexity compared to the best attack strategy. We also show that the proposed algorithms can be further improved by including cyclic redundancy check bits and parity check bits generated in the algorithms, for example, when polar codes or LDPC codes according to the 5G standard are used in the coding layer. Finally, we show the compatibility of the algorithms for both polar codes and LDPC codes.

In this paper we show a way to check semantic security for AWGN wiretap channels. We introduce low complexity decoding methods that provide upper and lower bounds to the performance of an attack strategy that closely resembles the best attack strategy, which has the problem of large computational complexity. We show the assumptions under which these methods can be applied and compare simulation results of the bounds to the performance of the best attack strategy. We use a seeded modular coding scheme, which consists of a coding layer and a security layer. For the coding layer we use polar codes, but the method is neither restricted to the seeded modular coding scheme nor to the polar codes.

We experimentally verify the information-theoretic security of a seeded modular code for the AWGN wiretap channel consisting of a security layer, an error-correction layer and a modulation layer. The security layer is given by a universal family of hash functions. In the error-correction layer and the modulation layer we use polar codes and QAM, respectively. The eavesdropper uses the maximum likelihood (ML) test as an attack strategy. We analyze the security in different communication scenarios using simulations. We show that for small blocklengths the advantage (security measure) at the eavesdropper in the corresponding scenario can be close to 0 for suitable code parameters. Additional insights gathered from the simulation results include the impact of code parameters and seed choice on security.

In this paper we use a seeded modular coding scheme for implementing physical layer security in a wiretap scenario. This modular scheme consists of a traditional coding layer and a security layer. For the traditional coding layer, we use a polar code. We evaluate the performance of the seeded modular coding scheme in an experimental setup with software defined radios and compare these results to simulation results. In order to assess the secrecy level of the scheme, we employ the distinguishing security metric. In our experiments, we compare the distinguishing error rate for different seeds and block lengths.