Audio steganography with AES for real-time covert Voice over Internet Protocol communications

As a popular real-time service on the Internet, Voice over Internet Protocol (VoIP) communication attracts more and more attention from the researchers in the information security field. In this study, we proposed a VoIP steganographic algorithm with variable embedding capacities, incorporating AES and key distribution, to realize a real-time covert VoIP communication. The covert communication system was implemented by embedding a secret message encrypted with symmetric cryptography AES-128 into audio signals encoded by PCM codec. At the beginning of each VoIP call, a symmetric session key (SK) was assigned to the receiver with a Session Initiation Protocol-based authentication method. The secret message was encrypted and then embedded into audio packets with different embedding algorithms before sending them, so as to meet the real-time requirements of VoIP communications. For each audio packet, the embedding capacity was calculated according to the specific embedding algorithm used. The encryption and embedding processes were almost synchronized. The time cost of encryption was so short that it could be ignored. As a result of AES-based steganography, observers could not detect the hidden message using simple statistical analysis. At the receiving end, the corresponding algorithm along with the SK was employed to retrieve the original secret message from the audio signals. Performance evaluation with state-of-the-art network equipment and security tests conducted using the Mann-Whitney-Wilcoxon method indicated that the proposed steganographic algorithm is secure, effective, and robust

Surrogate-Driven Multi-Objective Predictive Control for Electric Vehicular Platoon

This paper proposes a surrogate-driven multi-objective predictive control (SMPC) strategy to address the dynamics uncertainty and multi-objective optimization issues of electric vehicular platoon (EVP). A surrogate-driven model is established with subspace identification to alleviate the adverse effects of uncertain dynamics for EVP. Then, a subspace predictor-based distributed surrogate-driven model predictive controller is developed for EVP. To mitigate conflicts among multiple optimization objectives involving driving safety, driving comfort and energy economy, a multi-objective cost function with the predictive sequence is designed. To this end, a grey wolf optimizer is suggested to guide the search towards diverse solutions, aiming to achieve globally optimal trade-offs among conflicting multiple objectives. In this way, the SMPC strategy is constructed, and its stability is theoretically proven. Finally, several experiments are carried out on a co-simulation vehicular platoon platform with the IPG-CarMaker software. The experimental results validate the effectiveness of the proposed SMPC strategy

Geometry-independent antenna based on Epsilon-near-zero medium

It is well known that electromagnetic radiation from radiating elements (e.g., antennas, apertures, etc.) shows dependence on the element’s geometry shape in terms of operating frequencies. This basic principle is ubiquitous in the design of radiators in multiple applications spanning from microwave, to optics and plasmonics. The emergence of epsilon-near-zero media exceptionally allows for an infinite wavelength of electromagnetic waves, manifesting exotic spatially-static wave dynamics which is not dependent on geometry. In this work, we analyze theoretically and verify experimentally such geometry-independent features for radiation, thus presenting a novel class of radiating resonators, i.e., antennas, with an operating frequency irrelevant to the geometry shape while only determined by the host material’s dispersions. Despite being translated into different shapes and topologies, the designed epsilon-near-zero antenna resonates at a same frequency, while exhibiting very different far-field radiation patterns, with beams varying from wide to narrow, or even from single to multiple. Additionally, the photonic doping technique is employed to facilitate the high-efficiency radiation. The material-determined geometry-independent radiation may lead to numerous applications in flexible design and manufacturing for wireless communications, sensing, and wavefront engineering. © 2022, The Author(s).Y.L. acknowledges partial support from National Natural Science Foundation of China (NSFC) under grant 62022045, and in part by supported by Tsinghua University Initiative Scientific Research Program. I.L. acknowledges support from Ramón y Cajal fellowship RYC2018-024123-I, project RTI2018-093714-301J-I00 sponsored by MCIU/AEI/FEDER/UE, and ERC Starting Grant 948504

Gain and loss of function variants in EZH1 disrupt neurogenesis and cause dominant and recessive neurodevelopmental disorders

Autism spectrum disordersTrastorns de l'espectre autistaTrastornos del espectro autistaGenetic variants in chromatin regulators are frequently found in neurodevelopmental disorders, but their effect in disease etiology is rarely determined. Here, we uncover and functionally define pathogenic variants in the chromatin modifier EZH1 as the cause of dominant and recessive neurodevelopmental disorders in 19 individuals. EZH1 encodes one of the two alternative histone H3 lysine 27 methyltransferases of the PRC2 complex. Unlike the other PRC2 subunits, which are involved in cancers and developmental syndromes, the implication of EZH1 in human development and disease is largely unknown. Using cellular and biochemical studies, we demonstrate that recessive variants impair EZH1 expression causing loss of function effects, while dominant variants are missense mutations that affect evolutionarily conserved aminoacids, likely impacting EZH1 structure or function. Accordingly, we found increased methyltransferase activity leading to gain of function of two EZH1 missense variants. Furthermore, we show that EZH1 is necessary and sufficient for differentiation of neural progenitor cells in the developing chick embryo neural tube. Finally, using human pluripotent stem cell-derived neural cultures and forebrain organoids, we demonstrate that EZH1 variants perturb cortical neuron differentiation. Overall, our work reveals a critical role of EZH1 in neurogenesis regulation and provides molecular diagnosis for previously undefined neurodevelopmental disorders.This work was supported by the CHOP/UPENN IDDRC-New Program Development award, CHOP-Junior Faculty Pilot Program award, Margaret Q Landerbergen Foundation Award and NIH/NINDS R01NS119699, NIH/NICHD R21HD107592 (to N.A.), NIH/NINDS R35NS116843 (to H.S.), NIH/NINDS R35NS097370 and NIH/NIMH RF1MH123979 (to G.-l.M.)., BFU2015-69248-P and PGC2018-096082-B-I00 from the Spanish Ministry of Economy (to M.A.M.B.), Alabama Genomic Health Initiative F170303004 through University of Alabama at Birmingham (to A.C.H., M.T.), PID2019-111217RB-I00 Spanish Ministerio de Ciencia e Innovación (to X.D.L.C.), ID2019-110157RA-I00 (to M.S.), FPU Spanish Ministry of Education and Science predoctoral fellowship (to R.F.) and 2021 FISDU 00400 (to P.E-B.), NIHR Manchester Biomedical Research Centre NIHR203308 and Solve-RD which is supported by the European Union’s Horizon 2020 research and innovation program grant agreement No 779257 (to S.B.). This research was made possible through access to the data and findings generated by the 100KGP and the DDD. The 100KGP is managed by Genomics England Limited (a wholly owned company of the Department of Health and Social Care). The 100KGP is funded by the National Institute for Health Research and NHS England. The Wellcome Trust, Cancer Research UK and the Medical Research Council have also funded research infrastructure. The 100KGP uses data provided by patients and collected by the National Health Service as part of their care and support. The DDD study presents independent research commissioned by the Health Innovation Challenge Fund [grant number HICF-1009-003], a parallel funding partnership between Wellcome and the Department of Health, and the Wellcome Sanger Institute [grant number WT098051]. The views expressed in this publication are those of the author(s) and not necessarily those of Wellcome or the Department of Health. The study has UK Research Ethics Committee approval (10/H0305/83, granted by the Cambridge South REC, and GEN/284/12 granted by the Republic of Ireland REC). The research team acknowledges the support of the National Institute for Health Research, through the Comprehensive Clinical Research Network

Dispersion coding of ENZ media via multiple photonic dopants

Epsilon-near-zero (ENZ) media are opening up exciting opportunities to observe exotic wave phenomena. In this work, we demonstrate that the ENZ medium comprising multiple dielectric photonic dopants would yield a comb-like dispersion of the effective permeability, with each magnetic resonance dominated by one specific dopant. Furthermore, at multiple frequencies of interest, the resonant supercouplings appearing or not can be controlled discretely via whether corresponding dopants are assigned or not. Importantly, the multiple dopants in the ENZ host at their magnetic resonances are demonstrated to be independent. Based on this platform, the concept of dispersion coding is proposed, where photonic dopants serve as “bits” to program the spectral response of the whole composite medium. As a proof of concept, a compact multi-doped ENZ cavity is fabricated and experimentally characterized, whose transmission spectrum is manifested as a multi-bit reconfigurable frequency comb. The dispersion coding is demonstrated to fuel a batch of innovative applications including dynamically tunable comb-like dispersion profiled filters, radio-frequency identification tags, etc.© 2022, The Author(s).Y.L. acknowledges partial support from the National Natural Science Foundation of China (NSFC) under grant 62022045, and in part by the Beijing Nova Program of Science and Technology under Grant Z191100001119082, as well as the support from the Beijing National Research Center for Information Science and Technology. I.L. acknowledges support from project RTI2018-093714-J-I00 sponsored by MCIU/AEI/FEDER/UE