Abstract

Abstract

Abstract
Digital economy relies on global data exchange flows. On May 25th 2018 the GDPR came into force, representing a shift in data protection legislation by tightening data protection rules. This paper introduces an innovative solution that aims to diminish the burden resulting from new regulatory demands on all stakeholders. The presented solution allows the data controller to collect the consent, of a European citizen, in accordance to the GDPR and persist proof of said consent on public a blockchain. On the other hand, the data subject will be able to express his consent conveniently through his smartphone and evaluate the data controller’s performance. The regulator’s role was also contemplated, meaning that he can leverage certain system capabilities specifically designed to gauge the status of the relationships between data subjects and data controllers. © Springer Nature Switzerland AG 2020.

Abstract
In this work, we consider the pros and cons of using various layers of keyless coding to achieve secure and reliable communication over the Gaussian wiretap channel. We define a new approach to information theoretic security, called practical secrecy and the secrecy benefit, to be used over real-world channels and finite blocklength instantiations of coding layers, and use this new approach to show the fundamental reliability and security implications of several coding mechanisms that have traditionally been used for physical-layer security. We perform a systematic/structured analysis of the effect of error-control coding, scrambling, interleaving, and coset coding, as coding layers of a secrecy system. Using this new approach, scrambling and interleaving are shown to be of no effect in increasing information theoretic security, even when measuring the effect at the output of the eavesdropper's decoder. Error control coding is shown to present a trade-off between secrecy and reliability that is dictated by the chosen code and the signal-to-noise ratios at the legitimate and eavesdropping receivers. Finally, the benefits of secrecy coding are highlighted, and it is shown how one can shape the secrecy benefit according to system specifications using combinations of different layers of coding to achieve both reliable and secure throughput.

Abstract
In this paper, we fill a void between information theoretic security and practical coding over the Gaussian wiretap channel using a three-stage encoder/decoder technique. Security is measured using Kullback-Leibler divergence and resolvability techniques along with a limited number of practical assumptions regarding the eavesdropper's decoder. The results specify a general coding recipe for obtaining both secure and reliable communications over the Gaussian wiretap channel, and one specific set of concatenated codes is presented as a test case for the sake of providing simulation-based evaluation of security and reliability over the network. It is shown that there exists a threshold in signal-to-noise ratio (SNR) over a Gaussian channel, such that receivers experiencing SNR below the threshold have no practical hope of receiving information about the message when the three-stage coding technique is applied. Results further indicate that the two innermost encoding stages successfully approximate a binary symmetric channel, allowing the outermost encoding stage (e.g., a wiretap code) to focus solely on secrecy coding over this approximated channel.

Abstract
Index Modulation (IM) is a technique that activate k out of n subcarriers of an OFDM symbol to transmit p(1) = right perpendicularlog(2) (n k)left perpendicular bits in symbol's indexes. Since both the symbol's spectrum width and transmission air-time duration remain the same, OFDM-IM outperforms OFDM's Spectral Efficiency (SE) for larger values of (n k). However, OFDM-IM requires an extra step called Index Selector (IxS) which takes T-alpha time units to map a given p(1)-bit input to its corresponding pattern of active subcarriers. This extra overhead virtually enlarges the symbol duration, which is not captured by the classic SE definition. To fulfill this gap, in this work we present the Spectro-Computational Efficiency (SCE) metric. SCE parameterizes either the absolute runtime of T-alpha on a reference hardware or its computational complexity T-alpha(n; k) as function of n and k. Based on SCE, we present theoretical case studies to identify the asymptotic bounds for T-alpha(n, k) across different choices of k. if T-alpha(n, n=2) is at most linear on n the resulting overhead is asymptotically negligible and IxS can handle an arbitrarily large OFDM symbol. Otherwise, OFDM-IM's SCE tends to zero regardless of the hardware processor speed. Also, we situate the inflection-point values for OFDM-IM's SCE between (6 3) and (14 7) in some practical case studies.