The upcoming Sixth-Generation (6G) communication systems bring several challenges to systems security. The Secrecy Key Generation (SKG) is a Physical Layer Security (PLS) technique in which two trusted nodes negotiate a session key, taking advantage of the physical layer phenomena, i.e., radio propagation and/or hardware characteristics, as a source of entropy. In this contribution, we investigate the impact of the variation of the antenna radiation pattern on the SKG performance. We considered two legitimate nodes that apply the SKG to negotiate their session key, whereas a malicious node tries to eavesdrop on the communication to obtain the key by performing the on-the-shoulder attack. The results highlight how the number of antenna dipoles, the Half Power Beamwidth (HPBW) of the main lobe, and the presence of secondary lobes or minima of radiation influence the key mismatch between the legitimate nodes as well as the eavesdropper attack surface.
The upcoming Sixth-Generation (6G) communication systems bring several challenges to systems security. The Secrecy Key Generation (SKG) is a Physical Layer Security (PLS) technique in which two trusted nodes negotiate a session key, taking advantage of the physical layer phenomena, i.e., radio propagation and/or hardware characteristics, as a source of entropy. In this contribution, we investigate the impact of the variation of the antenna radiation pattern on the SKG performance. We considered two legitimate nodes that apply the SKG to negotiate their session key, whereas a malicious node tries to eavesdrop on the communication to obtain the key by performing the on-the-shoulder attack. The results highlight how the number of antenna dipoles, the Half Power Beamwidth (HPBW) of the main lobe, and the presence of secondary lobes or minima of radiation influence the key mismatch between the legitimate nodes as well as the eavesdropper attack surface.
The heterogeneous nature of the Sixth-Generation (6G) communication systems, jointly with the rapid expansion of sensitive applications, bring several challenges to systems security.The Secrecy Key Generation (SKG) is a Physical Layer Security (PLS) technique in which two legitimate nodes negotiate a session key, taking advantage of the physical layer phenomena as a source of entropy.In this contribution, we investigate the impact of Uniform Linear Array (ULA) dipole spacing on the SKG performance considering an indoor application environment.We considered two legitimate nodes, i.e., Alice and Bob, that adopt the SKG protocol to negotiate their session key.A malicious node, i.e., Eve, tries to eavesdrop on the communication to obtain the key by performing the on-the-shoulder attack.Results demonstrate that smaller dipole spacings, i.e., d ≤ 0.5λ result in lower channel and key correlations between Eve and the legitimate nodes, enhancing security.Larger spacings, however, create periodic zones of moderate correlation, potentially aiding Eve under certain angular positions.
Physical Layer Security (PLS) is emerging as an innovative solution to enhance the security of wireless communications. This work analyzes the impact of a realistic indoor radio propagation on Secrecy Key Generation (SKG) in a Wi-Fi application scenario. This PLS technique is based on the extraction of raw cryptographic keys, taking advantage of the radio propagation phenomena as a source of entropy. In detail, we considered two legitimate nodes, i.e., Alice and Bob, which use the SKG to extract keys from the channel, and a malicious node, i.e., Eve, which acts as a passive eavesdropper and tries to discover the key. The reported results show that legitimate nodes key mismatch is strongly influenced by noise contribution, and the eavesdropper attack performs better with a higher Line-of-Sight (LoS) contribution. Conversely, when the power is evenly spread over all the multipath components, the eavesdropped key mismatch is maintained in the range of 30 – 50 %.
Physical layer security (PLS) is seen as the means to enhance physical layer trustworthiness in 6G. This work provides a proof-of-concept for one of the most mature PLS technologies, i.e., secret key generation (SKG) from wireless fading coefficients during the channel’s coherence time. As opposed to other works, where only specific parts of the protocol are typically investigated, here, we implement the full SKG chain in four indoor experimental campaigns. In detail, we consider two legitimate nodes, who use the wireless channel to extract secret keys and a malicious node placed in the immediate vicinity of one of them, who acts as a passive eavesdropper. To estimate the final SKG rate we evaluate the conditional min-entropy by taking into account all information available at the eavesdropper. Finally, we use this paper to announce the first ever physical layer security challenge, mirroring practices in cryptography. We call the community to scrutinize the presented results and try to “break” our SKG implementation. To this end, we provide, i) the full dataset observed by the eavesdroppers, ii) 20 blocks of 16−byte long ciphertexts, encrypted using one-time pad with 20 distilled secret keys, and, iii) all codes and software used in our SKG implementation. An attack will be considered successful if any part(s) of the plaintext are successfully retrieved.
Physical layer security (PLS) is seen as the means to enhance physical layer trustworthiness in 6G. This work provides a proof-of-concept for one of the most mature PLS technologies, i.e., secret key generation (SKG) from wireless fading coefficients during the channel's coherence time. As opposed to other works, where only specific parts of the protocol are typically investigated, here, we implement the full SKG chain in four indoor experimental campaigns. In detail, we consider two legitimate nodes, who use the wireless channel to extract secret keys and a malicious node placed in the immediate vicinity of one of them, who acts as a passive eavesdropper. To estimate the final SKG rate we evaluate the conditional min-entropy by taking into account all information available at the eavesdropper. Finally, we use this paper to announce the first ever physical layer security challenge, mirroring practices in cryptography. We call the community to scrutinize the presented results and try to “break” our SKG implementation. To this end, we provide, i) the full dataset observed by the eavesdroppers, ii) 20 blocks of 16 - byte long ciphertexts, encrypted using one-time pad with 20 distilled secret keys, and, iii) all codes and software used in our SKG implementation. An attack will be considered successful if any part(s) of the plaintext are successfully retrieved.
The wireless channel is inherently an open medium which exposes wireless communication users to the risk of interception. The vulnerabilities of the wireless channel have led to the search for innovative and efficient security solutions at different levels of the network protocol. In particular, the physical layer level allows for implementing some security functions, such as key generation and exchange, by exploiting the intrinsic randomness of the wireless communication channel. In this paper, we analyze the effect of wireless channel and of antenna characteristics on physical layer security (PLS) key generation. The aim is to put in evidence the relation between physical quantities, such as radio channel characteristics or antenna directivity, with higher level secrecy performance indicators, such as the key mismatch between the different communication nodes and the key randomness. For this purpose, we developed a comprehensive numerical model, which implements all the different steps, from signal generation and wireless propagation modeling to key generation through spectral quantization. The reported results show that the multipath richness of the radio channel, as in outdoor urban scenarios, improves the PLS secrecy performances with respect to simpler propagation scenarios. Moreover, we show that the use of more directive antennas in the legitimate communication link improves secrecy. An opposite effect is achieved when the directivity of the eavesdropper antenna is increased, thus improving its ability to perform passive attacks.
Physical layer security (PLS) is seen as the means to enhance physical layer trustworthiness in 6G. This work provides a proof-of-concept for one of the most mature PLS technologies, i.e., secret key generation (SKG) from wireless fading coefficients during the channel’s coherence time. As opposed to other works, where only specific parts of the protocol are typically investigated, here, we implement the full SKG chain in four indoor experimental campaigns. In detail, we consider two legitimate nodes, who use the wireless channel to extract secret keys and a malicious node placed in the immediate vicinity of one of them, who acts as a passive eavesdropper. To estimate the final SKG rate we evaluate the conditional min-entropy by taking into account all information available at the eavesdropper. Finally, we use this paper to announce the first ever physical layer security challenge, mirroring practices in cryptography. We call the community to scrutinize the presented results and try to “break” our SKG implementation. To this end, we provide, i) the full dataset observed by the eavesdroppers, ii) 20 blocks of 16−byte long ciphertexts, encrypted using one-time pad with 20 distilled secret keys, and, iii) all codes and software used in our SKG implementation. An attack will be considered successful if any part(s) of the plaintext are successfully retrieved.