Revisiting Speech Content Privacy

In this paper, we discuss an important aspect of speech privacy: protecting spoken content. New capabilities from the field of machine learning provide a unique and timely opportunity to revisit speech content protection. There are many different applications of content privacy, even though this area has been under-explored in speech technology research. This paper presents several scenarios that indicate a need for speech content privacy even as the specific techniques to achieve content privacy may necessarily vary. Our discussion includes several different types of content privacy including recoverable and non-recoverable content. Finally, we introduce evaluation strategies as well as describe some of the difficulties that may be encountered.Comment: Accepted to ISCA Security and Privacy in Speech Communication (1st SPSC Symposium

SECURITY AND PRIVACY ISSUES IN MOBILE NETWORKS, DIFFICULTIES AND SOLUTIONS

Mobile communication is playing a vital role in the daily life for the last two decades; in turn its fields gained the research attention, which led to the introduction of new technologies, services and applications. These new added facilities aimed to ease the connectivity and reachability; on the other hand, many security and privacy concerns were not taken into consideration. This opened the door for the malicious activities to threaten the deployed systems and caused vulnerabilities for users, translated in the loss of valuable data and major privacy invasions. Recently, many attempts have been carried out to handle these concerns, such as improving systems’ security and implementing different privacy enhancing mechanisms. This research addresses these problems and provides a mean to preserve privacy in particular. In this research, a detailed description and analysis of the current security and privacy situation in the deployed systems is given. As a result, the existing shortages within these systems are pointed out, to be mitigated in development. Finally a privacy preserving prototype model is proposed. This research has been conducted as an extensive literature review about the most relevant references and researches in the field, using the descriptive and evaluative research methodologies. The main security models, parameters, modules and protocols are presented, also a detailed description of privacy and its related arguments, dimensions and factors is given. The findings include that mobile networks’ security along with users are vulnerable due to the weaknesses of the key exchange procedures, the difficulties that face possession, repudiation, standardization, compatibility drawbacks and lack of configurability. It also includes the need to implement new mechanisms to protect security and preserve privacy, which include public key cryptography, HIP servers, IPSec, TLS, NAT and DTLS-SRTP. Last but not least, it shows that privacy is not absolute and it has many conflicts, also privacy requires sophisticated systems, which increase the load and cost of the system.fi=Opinnäytetyö kokotekstinä PDF-muodossa.|en=Thesis fulltext in PDF format.|sv=Lärdomsprov tillgängligt som fulltext i PDF-format

Kablolu iletişim ağlarında yeni bir şifreleme tabanlı güvenlik uygulaması

06.03.2018 tarihli ve 30352 sayılı Resmi Gazetede yayımlanan “Yükseköğretim Kanunu İle Bazı Kanun Ve Kanun Hükmünde Kararnamelerde Değişiklik Yapılması Hakkında Kanun” ile 18.06.2018 tarihli “Lisansüstü Tezlerin Elektronik Ortamda Toplanması, Düzenlenmesi ve Erişime Açılmasına İlişkin Yönerge” gereğince tam metin erişime açılmıştır.Günümüzde haberleĢme teknolojileri hızla geliĢmekte ve güvenli iletiĢim önemli bir kavram olarak ortaya çıkmaktadır. Gerek askeri gerek sivil uygulamalar da yapılan bir görüĢmenin, düĢmanın ya da ticari bir rakibin eline geçmemesi için kullanılan ve geliĢtirilen birçok güvenli haberleĢme sistemi mevcuttur. Bu sistemler üzerindeki çalıĢmalar günümüzde hala güncelliğini korumaktadır. Ġnternet ortamında, uydu haberleĢmesinde, telsiz haberleĢmesinde, kablolu telefon hatları ve mobil telefonlarda bu teknolojiler kullanılmakta ve yeni teknikler geliĢtirilmektedir. Bu çalıĢmada Public Switched Telephone Network (PSTN) üzerinden güvenli haberleĢme için bir sistem tasarlanmıĢ ve gerçekleĢtirilmiĢtir. KonuĢma sinyali dijital sinyale çevrilip Ģifrelendikten sonra bir dial up modem aracılığıyla PSTN üzerinden alıcıya gönderilmektedir. Burada Ģifreleme için düĢük bellek ve iĢlem kapasitesine sahip sistemler için geliĢtirilmiĢ SEA ve XTEA algoritmaları kullanılmıĢtır. GerçekleĢtirilen sistem ile konuĢma sinyali Ģifrelenmeden önce bu sinyalin üzerine bir metin gizlenebilmektedir ve bu sayede sistemin güvenliği arttırılmıĢtır. Metin dosyası ses sinyali üzerine gömüldüğünde ses sinyalindeki bozulmaların kulakla algılanmayacak seviyede olmasına dikkat edilmiĢtir. Hattı dinleyen yetkisiz kiĢiler Ģifrelemeyi çözüp ses sinyalini elde etseler bile ses içindeki gizlenmiĢ veriyi algılayıp steganaliz yöntemleri ile elde etmeleri gerekmektedir. Ayrıca yapılan ikinci bir uygulamada, kısa aralıklarla Ģifreleme algoritmaları ile bu algoritmaların kullandıkları anahtarları değiĢtirilmiĢ ve bu değiĢimlerle ilgili bilgiler alıcı ile eĢ zamanlı çalıĢmanın sağlanması için gizli metin içinde gönderilmiĢtir. Böylece Ģifrenin kırılıp yapılan gizli haberleĢmenin içeriğinin elde edilmesi daha da zorlaĢtırılmıĢ ve sistem güvenliği arttırılmıĢtır.Today, communication technologies are developing rapidly and secure communication appears to be an important concept. There are many secure communication systems developed and used for protecting any conversation from an enemy or a trade rival in both military and civil applications. The works performed for these systems still remain up to date today. In the internet, the satellite communication, the radio communication, the wired telephone lines and the mobile phones, these technologies are being used and new techniques are being developed. In this work, a system for secure communication over Public Switched Telephone Network (PSTN) has been designed and realized. After the speech signal is converted to digital signal, the digital signal is encrypted and it is sent to receiver over PSTN by the dial-up modem. The SEA and XTEA algorithms which have been developed for low memory and process capacity, have been used for the encryption. With the developed system, before the encryption of the speech signal, a text can be hide into the signal. So the security of the system has been increased. When the text is embedded to the speech signal, it has been considered that the distortions in the signal are in unsensiblelevel fort he ears. Even if unauthorized persons listening the line can decrypt the encryption and obtain the speech signal, they have to detect and obtain the hidden data in the signal by using the steganalysis methods. In addition, the encryption algorithms and the keys of them have been changed in short periods and the information related with the changes has been sent in the hidden text for synchronization with the receiver. Thus, it is become harder to decrypt the encryption and to obtain the context of the hidden communication and the security of the system is increased

Privacy-preserving and Privacy-attacking Approaches for Speech and Audio -- A Survey

In contemporary society, voice-controlled devices, such as smartphones and home assistants, have become pervasive due to their advanced capabilities and functionality. The always-on nature of their microphones offers users the convenience of readily accessing these devices. However, recent research and events have revealed that such voice-controlled devices are prone to various forms of malicious attacks, hence making it a growing concern for both users and researchers to safeguard against such attacks. Despite the numerous studies that have investigated adversarial attacks and privacy preservation for images, a conclusive study of this nature has not been conducted for the audio domain. Therefore, this paper aims to examine existing approaches for privacy-preserving and privacy-attacking strategies for audio and speech. To achieve this goal, we classify the attack and defense scenarios into several categories and provide detailed analysis of each approach. We also interpret the dissimilarities between the various approaches, highlight their contributions, and examine their limitations. Our investigation reveals that voice-controlled devices based on neural networks are inherently susceptible to specific types of attacks. Although it is possible to enhance the robustness of such models to certain forms of attack, more sophisticated approaches are required to comprehensively safeguard user privacy

A configurable vector processor for accelerating speech coding algorithms

The growing demand for voice-over-packer (VoIP) services and multimedia-rich applications has made increasingly important the efficient, real-time implementation of low-bit rates speech coders on embedded VLSI platforms. Such speech coders are designed to substantially reduce the bandwidth requirements thus enabling dense multichannel gateways in small form factor. This however comes at a high computational cost which mandates the use of very high performance embedded processors. This thesis investigates the potential acceleration of two major ITU-T speech coding algorithms, namely G.729A and G.723.1, through their efficient implementation on a configurable extensible vector embedded CPU architecture. New scalar and vector ISAs were introduced which resulted in up to 80% reduction in the dynamic instruction count of both workloads. These instructions were subsequently encapsulated into a parametric, hybrid SISD (scalar processor)–SIMD (vector) processor. This work presents the research and implementation of the vector datapath of this vector coprocessor which is tightly-coupled to a Sparc-V8 compliant CPU, the optimization and simulation methodologies employed and the use of Electronic System Level (ESL) techniques to rapidly design SIMD datapaths

Recent Advances in Signal Processing

The signal processing task is a very critical issue in the majority of new technological inventions and challenges in a variety of applications in both science and engineering fields. Classical signal processing techniques have largely worked with mathematical models that are linear, local, stationary, and Gaussian. They have always favored closed-form tractability over real-world accuracy. These constraints were imposed by the lack of powerful computing tools. During the last few decades, signal processing theories, developments, and applications have matured rapidly and now include tools from many areas of mathematics, computer science, physics, and engineering. This book is targeted primarily toward both students and researchers who want to be exposed to a wide variety of signal processing techniques and algorithms. It includes 27 chapters that can be categorized into five different areas depending on the application at hand. These five categories are ordered to address image processing, speech processing, communication systems, time-series analysis, and educational packages respectively. The book has the advantage of providing a collection of applications that are completely independent and self-contained; thus, the interested reader can choose any chapter and skip to another without losing continuity

The dawn of the human-machine era: a forecast of new and emerging language technologies

New language technologies are coming, thanks to the huge and competing private investment fuelling rapid progress; we can either understand and foresee their effects, or be taken by surprise and spend our time trying to catch up. This report scketches out some transformative new technologies that are likely to fundamentally change our use of language. Some of these may feel unrealistically futuristic or far-fetched, but a central purpose of this report - and the wider LITHME network - is to illustrate that these are mostly just the logical development and maturation of technologies currently in prototype. But will everyone benefit from all these shiny new gadgets? Throughout this report we emphasise a range of groups who will be disadvantaged and issues of inequality. Important issues of security and privacy will accompany new language technologies. A further caution is to re-emphasise the current limitations of AI. Looking ahead, we see many intriguing opportunities and new capabilities, but a range of other uncertainties and inequalities. New devices will enable new ways to talk, to translate, to remember, and to learn. But advances in technology will reproduce existing inequalities among those who cannot afford these devices, among the world's smaller languages, and especially for sign language. Debates over privacy and security will flare and crackle with every new immersive gadget. We will move together into this curious new world with a mix of excitement and apprehension - reacting, debating, sharing and disagreeing as we always do. Plug in, as the human-machine era dawn

On privacy in mobile voice communication networks

The introduction of mobile communications has undoubtedly altered our physical and social world. Like the Internet, it has changed the way we interact with each other allowing for communication using a variety of communication mediums by means of a magnitude of interactive mobile devices. The context, content, persons communicating, situation and timing all have a varying degree of influence on the sensitivity of information being shared. The individual's awareness of exposure of their private information on the Internet has filtered through into the mobile communications space. It is commonly held in current mobile communication network literature that as privacy-sensitive information travels through a network, it may be exposed to privacy infringement at various stages along its journey. Much of the concern from the individual's perspective, though, stems from a fear of the unknown. In the presence of these threats and vulnerabilities it is justified to wonder whether current mobile communications networks (and indeed future networks) provides sufficient privacy for users with very valuable information to communicate. In this thesis, I develop a systematic approach to identifying areas of privacy concern in a current mobile communication networks in an effort to outline mobile communication privacy principles and how applicable they are in Next Generation Networks. With a privacy stance, the objective of my work is through technical examination and sometimes theoretical undertaking to identify acceptable solutions which restrict the flow of private information and ultimately confirm, through privacy analyses, the benefits gained in doing so. The results show that, given the current situation and technological configuration, there are commonalities which extend beyond a mere concern within a mobile communications network's requirement for privacy enhancement. In a perfect world, the idea is to articulate towards a system of privacy by design rather than as an uttered afterthought. It is no longer inconceivable to think there is an opportunity to deliver a privacy-conscious network, if careful consideration is given to all parties and aspects that govern a mobile communications network and the correct privacy-enhancing technologies are administered correctly. Throughout my thesis, although each privacy solution is segmented and may have a specific privacy application, the results attested contribute largely to a converged prospectus for privacy-aware future generation communication networks. The significance of this lies in the study of past privacy pitfalls in order to better manage the potential for future privacy problems. The rationalisation is if privacy principles are identified (in existing networks) and adhered and applied to (in next generation networks), then we converge towards a network infrastructure that possesses a desirable level of privacy protection.Thesis (PhD)--University of Pretoria, 2011.Computer Scienceunrestricte

Quality of media traffic over Lossy internet protocol networks: Measurement and improvement.

Voice over Internet Protocol (VoIP) is an active area of research in the world of communication. The high revenue made by the telecommunication companies is a motivation to develop solutions that transmit voice over other media rather than the traditional, circuit switching network. However, while IP networks can carry data traffic very well due to their besteffort nature, they are not designed to carry real-time applications such as voice. As such several degradations can happen to the speech signal before it reaches its destination. Therefore, it is important for legal, commercial, and technical reasons to measure the quality of VoIP applications accurately and non-intrusively. Several methods were proposed to measure the speech quality: some of these methods are subjective, others are intrusive-based while others are non-intrusive. One of the non-intrusive methods for measuring the speech quality is the E-model standardised by the International Telecommunication Union-Telecommunication Standardisation Sector (ITU-T). Although the E-model is a non-intrusive method for measuring the speech quality, but it depends on the time-consuming, expensive and hard to conduct subjective tests to calibrate its parameters, consequently it is applicable to a limited number of conditions and speech coders. Also, it is less accurate than the intrusive methods such as Perceptual Evaluation of Speech Quality (PESQ) because it does not consider the contents of the received signal. In this thesis an approach to extend the E-model based on PESQ is proposed. Using this method the E-model can be extended to new network conditions and applied to new speech coders without the need for the subjective tests. The modified E-model calibrated using PESQ is compared with the E-model calibrated using i ii subjective tests to prove its effectiveness. During the above extension the relation between quality estimation using the E-model and PESQ is investigated and a correction formula is proposed to correct the deviation in speech quality estimation. Another extension to the E-model to improve its accuracy in comparison with the PESQ looks into the content of the degraded signal and classifies packet loss into either Voiced or Unvoiced based on the received surrounding packets. The accuracy of the proposed method is evaluated by comparing the estimation of the new method that takes packet class into consideration with the measurement provided by PESQ as a more accurate, intrusive method for measuring the speech quality. The above two extensions for quality estimation of the E-model are combined to offer a method for estimating the quality of VoIP applications accurately, nonintrusively without the need for the time-consuming, expensive, and hard to conduct subjective tests. Finally, the applicability of the E-model or the modified E-model in measuring the quality of services in Service Oriented Computing (SOC) is illustrated