Security and Privacy for Ubiquitous Mobile Devices

We live in a world where mobile devices are already ubiquitous. It is estimated that in the United States approximately two thirds of adults own a smartphone, and that for many, these devices are their primary method of accessing the Internet. World wide, it is estimated that in May of 2014 there were 6.9 billion mobile cellular subscriptions, almost as much as the world population. of these 6.9 billion, approximately 1 billion are smart devices, which are concentrated in the developed world. In the developing world, users are moving from feature phones to smart devices as a result of lower prices and marketing efforts. Because smart mobile devices are ubiquitous, security and privacy are primary concerns. Threats such as mobile malware are already substantial, with over 2500 different types identified in 2010 alone. It is likely that, as the smart device market continues to grow, so to will concerns about privacy, security, and malicious software. This is especially true, because these mobile devices are relatively new. Our research focuses on increasing the security and privacy of user data on smart mobile devices. We propose three applications in this domain: (1) a service that provides private, mobile location sharing; (2) a secure, intuitive proximity networking solution; and (3) a potential attack vector in mobile devices, which utilizes novel covert channels. We also propose a first step defense mechanism against these covert channels. Our first project is the design and implementation of a service, which provides users with private and secure location sharing. This is useful for a variety of applications such as online dating, taxi cab services, and social networking. Our service allows users to share their location with one another with trust and location based access controls. We allow users to identify if they are within a certain distance of one another, without either party revealing their location to one another, or any third party. We design this service to be practical and efficient, requiring no changes to the cellular infrastructure and no explicit encryption key management for the users. For our second application, we build a modem, which enables users to share relatively small pieces of information with those that are near by, also known as proximity based networking. Currently there are several mediums which can be used to achieve proximity networking such as NFC, bluetooth, and WiFi direct. Unfortunately, these currently available schemes suffer from a variety of drawbacks including slow adoption by mobile device hardware manufactures, relatively poor usability, and wide range, omni-directional propagation. We propose a new scheme, which utilizes ultrasonic (high frequency) audio on typical smart mobile devices, as a method of communication between proximal devices. Because mobile devices already carry the necessary hardware for ultrasound, adoption is much easier. Additionally, ultrasound has a limited and highly intuitive propagation pattern because it is highly directional, and can be easily controlled using the volume controls on the devices. Our ultrasound modem is fast, achieving several thousand bits per second throughput, non-intrusive because it is inaudible, and secure, requiring attackers with normal hardware to be less than or equal to the distance between the sender and receiver (a few centimeters in our tests). Our third work exposes a novel attack vector utilizing physical media covert channels on smart devices, in conjunction with privilege escalation and confused deputy attacks. This ultimately results in information leakage attacks, which allow the attacker to gain access to sensitive information stored on a user\u27s smart mobile device such as their location, passwords, emails, SMS messages and more. Our attack uses our novel physical media covert channels to launder sensitive information, thereby circumventing state of the art, taint-tracking analysis based defenses and, at the same time, the current, widely deployed permission systems employed by mobile operating systems. We propose and implement a variety of physical media covert channels, which demonstrate different strengths such as high speed, low error rate, and stealth. By proposing several different channels, we make defense of such an attack much more difficult. Despite the challenging situation, in this work we also propose a novel defense technique as a first step towards research on more robust approaches. as a contribution to the field, we present these three systems, which together enrich the smart mobile experience, while providing mobile security and keeping privacy in mind. Our third approach specifically, presents a unique attack, which has not been seen in the wild , in an effort to keep ahead of malicious efforts

A New Covert Channel Over Cellular Network Voice Channel

Smartphone security has become increasingly more significant as smartphones become a more important part of many individuals\u27 daily lives. Smartphones undergo all computer security issues; however, they also introduce a new set of security issues as various capabilities are added. Smartphone security researchers pay more attention to security issues inherited from the traditional computer security field than smartphone-related security issues. The primary network that smartphones are connected to is the cellular network, but little effort has been directed at investigating the potential security issues that could threaten this network and its end users. A new possible threat that could occur in the cellular network is introduced in this paper. This research proves the ability to use the cellular network voice channel as a covert channel that can convey covert information as speech, thus breaking the network policies. The study involves designing and implementing multiple subsystems in order to prove the theory. First, a software audio modem that is able to convert digital data into audio waves and inject the audio waves to the GSM voice channel was developed. Moreover, a user-mode rootkit was implemented in order to open the voice channels by stealthily answering the incoming voice call, thus breaking the security mechanisms of the smartphone. Multiple scenarios also were tested in order to verify the effectiveness of the proposed covert channel. The first scenario is a covert communication between two parties that intends to hide their communications by using a network that is unknown to the adversary and not protected by network security guards. The two parties communicate through the cellular network voice channel to send and receive text messages. The second scenario is a side channel that is able to leak data such as SMS or the contact of a hacked smartphone through the cellular network voice channel. The third scenario is a botnet system that uses the voice channel as command and control channel (C2). This study identifies a new potential smartphone covert channel, so the outcome should be setting countermeasures against this kind of breach

Digital acoustic communication in air using parametric loudspeaker

We propose an acoustic communication system using parametric loudspeaker that emits a communication signal into a limited area. We found that the use of minimum shift keying is suitable, since it has the potential and second harmonic signal that occur when the emit signal is distorted during propagation due to the effect of air. Experiments revealed that the proposed system emits an audible signal to a limited area, achieves a BER of 10−3 at Eb/N0 of 10 dB. Thus, it outperforms benchmarks using other modulation schemes

Experience: Design, Development and Evaluation of a Wearable Device for mHealth Applications

Wrist-worn devices hold great potential as a platform for mobile health (mHealth) applications because they comprise a familiar, convenient form factor and can embed sensors in proximity to the human body. Despite this potential, however, they are severely limited in battery life, storage, bandwidth, computing power, and screen size. In this paper, we describe the experience of the research and development team designing, implementing and evaluating Amulet – an open-hardware, open-software wrist-worn computing device – and its experience using Amulet to deploy mHealth apps in the field. In the past five years the team conducted 11 studies in the lab and in the field, involving 204 participants and collecting over 77,780 hours of sensor data. We describe the technical issues the team encountered and the lessons they learned, and conclude with a set of recommendations. We anticipate the experience described herein will be useful for the development of other research-oriented computing platforms. It should also be useful for researchers interested in developing and deploying mHealth applications, whether with the Amulet system or with other wearable platforms

Cyclist-aware intelligent transportation system

Abstract. Rapidly developing cities make cycling popular way of traveling around and with enhanced smart traffic light infrastructure cycling can be safer and smoother. Smartphones with an internet connectivity and advanced positioning sensors can be used to build a cost-effective infrastructure to enable cyclist-aware traffic lights system. However, such systems depends on proper time of arrival estimation which can be affected by the GPS errors which works poorly in area with tall buildings and driver behaviour. In this paper we discuss how presence of feedback from smart traffic system influence the driver awareness of the cyclist and affects the negative impact of time of arrival estimation errors. This paper gives an analysis of the existing approaches to build smart cyclist-aware traffic systems and different sources of errors that affects their performance. With designed computer appliance we evaluated the effectiveness of cyclist-aware system with and without a presence of additional haptic and audio feedback. The results show that the presence of feedback positively affects the driver awareness of cyclist and allow them to react earlier. Experiment shows that just introduction of feedback can increase the accuracy of time of arrival estimation up to 34% without any other modification to the system.Pyöräilijät tiedostava älykäs liikennejärjestelmä. Tiivistelmä. Pyöräily on suosittu tapa liikkua nopeasti kasvavissa kaupungeissa. Parannetuilla älyliikennevaloilla pyöräilystä voisi tulla turvallisempaa ja sujuvampaa. Huokean infrastruktuurin rakentamisessa pyöräilijät tiedostavaan liikennevalojärjestelmään voidaan hyödyntää älypuhelinten verkkoyhteyttä sekä pitkälle kehitettynyttä paikannusmahdollisuutta. Paikannuksen haasteena kuitenkin ovat epätarkkuus korkeiden rakennusten katveessa sekä pyöräilijöiden ja autoilijoiden käyttäytyminen. Kyseisen kaltainen järjestelmä vaatii toimivan kulunaika-arvioinnin, mikä on haastavaa GPS-paikannuksen epätarkkuuden vuoksi. Tässä julkaisussa keskustelemme siitä, kuinka älykkäästä liikennejärjestelmästä saatu palaute vaikuttaa autoilijoiden tiedostavuuteen ja sitä kautta saapumisaika-arvioiden epätarkkuuteen. Analysoimme olemassa olevia älykkäitä pyöräiljät tiedostavia liikennejärjestelmiä ja niihin vaikuttavia epätarkkuus- sekä virhelähteitä. Käytämme kehittämäämme tietokone ohjelmaa arvioimaan pyöräilijät tiedostavan järjestelmän tehokkuutta käyttäen koemuuttujina haptista ja auditiivista palautetta. Tulokset paljastavat, että saatu palaute vaikuttaa positiivisesti parantaen autoilijoiden reaktioaikaa sekä sitä kuinka he tiedostavat pyöräiljät. Kokeet osoittavat, että pelkästään esittelyn ja palautteen olemassaolo lisäävät saapumisaika-arvioiden tarkkuutta jopa 34%

An Analysis of Vulnerabilities Presented by Android Malware and Ios Jailbreaks

Mobile devices are increasingly becoming a greater crutch for all generations. All the while, these users are garnering a greater desire for privacy and style. Apple presents a device that is known for its security, but lacks major user customization. On the other hand, Google has developed a device that is keen to customization with Android, but can be susceptible to security flaws. This thesis strives to discuss the security models, app store protections, and best practices of both mobile operating systems. In addition, multiple experiments were conducted to demonstrate how an Android device could be more easily compromised after altering few settings, as well as to demonstrate the privileges, both good and bad, that could be gained by jailbreaking an iOS device

An Analysis of Vulnerabilities Presented by Android Malware and Ios Jailbreaks

Mobile devices are increasingly becoming a greater crutch for all generations. All the while, these users are garnering a greater desire for privacy and style. Apple presents a device that is known for its security, but lacks major user customization. On the other hand, Google has developed a device that is keen to customization with Android, but can be susceptible to security flaws. This thesis strives to discuss the security models, app store protections, and best practices of both mobile operating systems. In addition, multiple experiments were conducted to demonstrate how an Android device could be more easily compromised after altering few settings, as well as to demonstrate the privileges, both good and bad, that could be gained by jailbreaking an iOS device

처프 신호를 이용한 음파 통신 기법 연구

학위논문 (박사)-- 서울대학교 대학원 : 전기·컴퓨터공학부, 2014. 8. 최성현.Todays smart devices such as smartphones and tablet/wearable PCs are equipped with voice user interface (UI) in order to support intuitive command input from users. Speakers and microphones of the voice UI are generally used to play and record human voice and/or environmental sound, respectively. Accordingly, various aerial acoustic communication techniques have been introduced to utilize the voice UI as an additional communication interface beyond WiFi and/or Bluetooth. Smart devices are especially suitable for the aerial acoustic communication since the application processor (AP) of smart devices can process the sound to embed or fetch information in it. That is, smart devices work similar to software defined radio platform. The aerial acoustic communication is also very versatile as any audio interface can be utilized as a communication interface. In this dissertation, we propose an aerial acoustic communication technique using inaudible chirp signal as well as corresponding receiver architecture for smart devices. We additionally introduce the applications of the proposed communication technique in indoor environments. We begin the receiver design for aerial acoustic communication by measuring the characteristics of indoor acoustic channel, composed of speaker, air-medium, and microphone. Our experimental research reveals that the indoor acoustic channel typically has long delay spread (approximately 40 msec), and it is very frequency-selective due to the frequency response of audio interfaces. We also show that legacy physical layer (PHY) modulation schemes such as phase/frequency shift keying (PSK/FSK) are likely to fail in this indoor acoustic channel, especially in long communication scenarios, due mainly to the instability of local oscillator and frequency selectivity of audio interfaces. In order to resolve the above-mentioned problems, we use chirp signals for the aerial acoustic communication. The proposed acoustic receiver supports long-range communication independent of the device characteristics over the severely frequency-selective acoustic channel with large delay spread. The chirp signal has time-varying frequency with a specific frequency sweeping rate. The chirp signal was widely used for radar applications due to its capability of resolving multi-path propagation. However, this dissertation is the first study of adopting chirp signal in aerial acoustic communications for smart devices. The proposed receiver architecture of chirp binary orthogonal keying (BOK) can be easily implemented via fast Fourier transform (FFT) in smart devices application layer. Via extensive experimental results, we verify that the proposed chirp signal can deliver data at 16 bps up to 25 m distance in typical indoor environments, which is drastically extended compared to the few meters of previous research. The data rate of 16 bps is enough to deliver short identification (ID) in indoor environments. The exemplary applications with this short ID can be multimedia content recognition and indoor location tracking. The low data rate, however, might be a huddle of the proposed system to be applied to the services that require high data rate. We design a backend server architecture in order to compensate for the low data rate and widen the application extent of the proposed receiver. The smart devices can send queries in order to refer to the backend server for additional information that is related with the received ID. We also propose an energy-efficient recording and processing method for the acoustic signal detection. Note that it would consume huge amount of energy if the smart devices contiguously sensed the acoustic signal for 24 hours. The smart devices instead control the sensing (i.e., recording) timing so that it is activated only when there exists chirp signal. This can drastically extend the battery lifetime by removing unnecessary signal processing. We also present two application examples of the proposed receiver, namely, (1) TV content recognition, and (2) indoor location tracking, including technical discussions on their implementations. Experiments and field tests validate the feasibility of the proposed aerial acoustic communication in practical environments.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 1.1 Acoustic communication . . . . . . . . . . . . . . . . . 1 1.1.1 Underwater acoustic communication . . . . . 2 1.1.2 Aerial acoustic communication . . . . . . . . . . 3 1.2 Overview of Existing Approaches . . . . . . . . . . . 5 1.2.1 Indoor Location Tracking . . . . . . . . . . . . . . . 5 1.2.2 Data Communication using Acoustic Signal . 7 1.2.3 Commercial Services . . . . . . . . . . . . . . . . . . 9 1.2.4 Limitations of Previous Work . . . . . . . . . . . 10 1.3 Main Contributions . . . . . . . . . . . . . . . . . . . . . 11 1.3.1 Acoustic Channel and PHY Analysis . . . . . . 12 1.3.2 Receiver Design for Acoustic Chirp BOK . . . 12 1.3.3 Applications of Chirp BOK Receiver . . . . . . 13 1.4 Organization of the Dissertation . . . . . . . . . . 13 2 Acoustic Channel and PHY Analysis . . . . . . . . . . 15 2.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . 15 2.2 Characteristics of Indoor Acoustic Channel . . 18 2.2.1 Hearing Threshold of Human . . . . . . . . . . . 18 2.2.2 Frequency Response of Various Audio Interfaces . 21 2.2.3 Delay Spread of Acoustic Channel . . . . . . . . 25 2.3 Revisit of Existing Modulation Schemes . . . . . . 26 2.3.1 Case Study: Phase Shift Keying . . . . . . . . . . 28 2.3.2 Case Study: Frequency Shift Keying . . . . . . . 35 2.3.3 Chirp Binary Orthogonal Keying (BOK) . . . . 40 2.4 Performance Evaluation of PHY Modulation Schemes . 42 2.4.1 Experimental Environment . . . . . . . . . . . . . . 44 2.4.2 PSK Demodulator . . . . . . . . . . . . . . . . . . . . . 44 2.4.3 FSK Demodulator . . . . . . . . . . . . . . . . . . . . . 45 2.4.4 BER of PHY Modulation Schemes . . . . . . . . . 46 2.5 Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 47 3 Receiver Design for Acoustic Chirp BOK . . . . . . . 49 3.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . 49 3.2 Chirp Signals and Matched Filter Receiver . . . . . 51 3.2.1 Notation of Chirp Signals . . . . . . . . . . . . . . . 51 3.2.2 Matched Filter and FFT . . . . . . . . . . . . . . . . . 53 3.2.3 Envelope Detection of Chirp Auto Correlation . 55 3.3 System Design and Receiver Architecture . . . . . . 59 3.3.1 Frame and Symbol Design . . . . . . . . . . . . . . . 60 3.3.2 Signal Reception Process . . . . . . . . . . . . . . . . 63 3.3.3 Receiver Architecture . . . . . . . . . . . . . . . . . . . 65 3.3.4 Symbol combining for BER enhancement . . . . 68 3.4 Performance Evaluation of Chirp BOK Receiver . . 73 3.4.1 Experimental Environment . . . . . . . . . . . . . . . . 74 3.4.2 Transmission Range in Indoor Environment . . . 74 3.4.3 Multi-path Resolution Capability of Chirp Signal . 75 3.4.4 Symbol Sampling and Doppler Shift . . . . . . . . . 82 3.4.5 Selective combining . . . . . . . . . . . . . . . . . . . . . 85 3.5 Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 87 4 Applications of Chirp BOK Receiver . . . . . . . . . . . . . . 90 4.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 90 4.2 Backend Server Architecture . . . . . . . . . . . . . . . . . . 93 4.2.1 Implementation of Backend Server . . . . . . . . . . 93 4.2.2 Operation of Backend Server . . . . . . . . . . . . . . 95 4.3 Low Power Operation for Smart Devices . . . . . . . . 98 4.3.1 Reception Process of Chirp BOK receiver . . . . . . 98 4.3.2 Revisit of Signal Detection in Wireless Communications ... 100 4.3.3 Chirp Signal Detection using PSD . . . . . . . . . . . 102 4.3.4 Performance Evaluation of Signal Detection Algorithm . 105 4.4 Applications of Chirp BOK Receiver and Feasibility Test . . 110 4.4.1 TV Content Recognition . . . . . . . . . . . . . . . . . . . 111 4.4.2 Indoor Location Tracking in Seoul Subway . . . . . 114 4.4.3 Device to Device Communication . . . . . . . . . . . . 118 4.5 Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 120 5 Conclusion and Future Work . . . . . . . . . . . . . . . . . . . 123 5.1 Research Contributions . . . . . . . . . . . . . . . . . . . . . . 123 5.2 Future Work and Concluding Remark . . . . . . . . . . 125 Abstract (In Korean) . . . . . . . . . . . . . . . . . . . . . . . . 136Docto

Adaptive Control of IoT/M2M Devices in Smart Buildings using Heterogeneous Wireless Networks

With the rapid development of wireless communication technology, the Internet of Things (IoT) and Machine-to-Machine (M2M) are becoming essential for many applications. One of the most emblematic IoT/M2M applications is smart buildings. The current Building Automation Systems (BAS) are limited by many factors, including the lack of integration of IoT and M2M technologies, unfriendly user interfacing, and the lack of a convergent solution. Therefore, this paper proposes a better approach of using heterogeneous wireless networks consisting of Wireless Sensor Networks (WSNs) and Mobile Cellular Networks (MCNs) for IoT/M2M smart building systems. One of the most significant outcomes of this research is to provide accurate readings to the server, and very low latency, through which users can easily control and monitor remotely the proposed system that consists of several innovative services, namely smart parking, garden irrigation automation, intrusion alarm, smart door, fire and gas detection, smart lighting, smart medication reminder, and indoor air quality monitoring. All these services are designed and implemented to control and monitor from afar the building via our free mobile application named Raniso which is a local server that allows remote control of the building. This IoT/M2M smart building system is customizable to meet the needs of users, improving safety and quality of life while reducing energy consumption. Additionally, it helps prevent the loss of resources and human lives by detecting and managing risks.Comment: Accepted in IEEE Sensors Journa

Agricultural LoRA sensor network applied to soil moisture monitoring for fertigation-based production

Mestrado de dupla diplomação com a Université Libre de TunisThe global water crisis is one of the serious threats that human being is facing and especially farmers due to a variety of environment issues. This growing trend of water scarcity led to the existence of the efficiency of irrigation systems for agricultural proposes using electronic sensors and performance systems to precise the amount of water for the growth of plants. However, currently, some automation attempts led to a sub-optimal solution as they do not take into account the vegetative development state of the plants and the small differences in environmental conditions present inside greenhouses. In this project, the work is based on developping a monitoring system based on measurement nodes for real-time monitoring temperature, and humidity. Open-source hardware and sensors was use to create the measurement nodes using LoRa WAN a wireless sensor network. The aim of this work is to create a network of sensors inside a greenhouse in order to obtain regularly updated information. The data is going to be useful since is easy to utilize by the farmers directly from a platform. Measurement node, communicating in real-time through LoRa, will transmit data to the gateway which will then be displayed on a dashboard.The classic internet is a global system of interconnected computer networks which carries a vast range of information resources and services in which HTTP (Hypertext Transfer Protocol) is the first protocol used to transfer hypertext data, from server to the end customer. The classic internet is thus based on the internet of data. On the other hand, the internet of things (IoT), is a new tool for connectivity and mobility, that is to transform business and is helpful in daily life to connect objects. Nowadays, common objects become active and intelligent, integrating seamlessly into a global network and can produce and exchange useful data without the intervention of humans. It’s a network of networks that allows us to identify and communicate digitally with the physical and virtual world. In the near future, the IoT will cover a wide range of applications in our daily life. The world is experiencing a huge increase of intelligent objects, that has led cloud service companies to make platforms known as the Internet of things platforms (IoT platform), which contain services, statistics, libraries, analyses that facilitate communication as well as accelerate and reduce the cost of product development of IoT applications