Asynchronous Ultrasonic Trilateration for Indoor Positioning of Mobile Phones

Spatial awareness is fast becoming the key feature on today‟s mobile devices. While accurate outdoor navigation has been widely available for some time through Global Positioning Systems (GPS), accurate indoor positioning is still largely an unsolved problem. One major reason for this is that GPS and other Global Navigation Satellite Systems (GNSS) systems offer accuracy of a scale far different to that required for effective indoor navigation. Indoor positioning is also hindered by poor GPS signal quality, a major issue when developing dedicated indoor locationing systems. In addition, many indoor systems use specialized hardware to calculate accurate device position, as readily available wireless protocols have so far not delivered sufficient levels of accuracy. This research aims to investigate how the mobile phone‟s innate ability to produce sound (notably ultrasound) can be utilised to deliver more accurate indoor positioning than current methods. Experimental work covers limitations of mobile phone speakers in regard to generation of high frequencies, propagation patternsof ultrasound and their impact on maximum range, and asynchronous trilateration. This is followed by accuracy and reliability tests of an ultrasound positioning system prototype.This thesis proposes a new method of positioning a mobile phone indoors with accuracy substantially better than other contemporary positioning systems available on off-theshelf mobile devices. Given that smartphones can be programmed to correctly estimate direction, this research outlines a potentially significant advance towards a practical platform for indoor Location Based Services. Also a novel asynchronous trilateration algorithm is proposed that eliminates the need for synchronisation between the mobile device and the positioning infrastructure

Survey and Systematization of Secure Device Pairing

Secure Device Pairing (SDP) schemes have been developed to facilitate secure communications among smart devices, both personal mobile devices and Internet of Things (IoT) devices. Comparison and assessment of SDP schemes is troublesome, because each scheme makes different assumptions about out-of-band channels and adversary models, and are driven by their particular use-cases. A conceptual model that facilitates meaningful comparison among SDP schemes is missing. We provide such a model. In this article, we survey and analyze a wide range of SDP schemes that are described in the literature, including a number that have been adopted as standards. A system model and consistent terminology for SDP schemes are built on the foundation of this survey, which are then used to classify existing SDP schemes into a taxonomy that, for the first time, enables their meaningful comparison and analysis.The existing SDP schemes are analyzed using this model, revealing common systemic security weaknesses among the surveyed SDP schemes that should become priority areas for future SDP research, such as improving the integration of privacy requirements into the design of SDP schemes. Our results allow SDP scheme designers to create schemes that are more easily comparable with one another, and to assist the prevention of persisting the weaknesses common to the current generation of SDP schemes.Comment: 34 pages, 5 figures, 3 tables, accepted at IEEE Communications Surveys & Tutorials 2017 (Volume: PP, Issue: 99

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

Ultrasonic Time Synchronization and Ranging on Smartphones

Abstract-In this paper, we present the design and evaluation of a platform that can be used for time synchronization and indoor positioning of mobile devices. The platform uses the Time-Difference-Of-Arrival (TDOA) of multiple ultrasonic chirps broadcast from a network of beacons placed throughout the environment to find an initial location as well as synchronize a receiver's clock with the infrastructure. These chirps encode identification data and ranging information that can be used to compute the receiver's location. Once the clocks have been synchronized, the system can continue performing localization directly using Time-of-Flight (TOF) ranging as opposed to TDOA. This provides similar position accuracy with fewer beacons (for tens of minutes) until the mobile device clock dirfts enough that a TDOA signal is once again required. Our hardware platform uses RF-based time synchronization to distribute clock synchronization from a subset of infrastructure beacons connected to a GPS source. Mobile devices use a novel time synchronization technique leverages the continuously freerunning audio sampling subsystem of a smartphone to synchronize with global time. Once synchronized, each device can determine an accurate proximity from as little as one beacon using Time-Of-Flight (TOF) measurements. This significantly decreases the number of beacons required to cover an indoor space and improves performance in the face of obstructions. We show through experiments that this approach outperforms the Network Time Protocol (NTP) on smartphones by an order of magnitude, providing an average 720µs synchronization accuracy with clock drift rates as low as 2ppm

Acoustic sensor

A method of designing and manufacturing an acoustic sensor having a high degree of directivity is disclosed. The sensor includes a rotatable plate that is attached to a substrate with mounts. In one aspect the mounts are freely rotatable and the torque on the plate is measured using detectors disposed on springs that provide a resistance to rotation of the plate. In another aspect the plate is mounted to the substrate with mounts that torsionally deform during rotation of the plate. These detectors measure the torque on the plate according to the torsional deformation of the mounts. Methods of improving the signal to noise ratio of acoustic sensors having multiple detectors are also disclosed.Board of Regents, University of Texas Syste

Acoustic Integrity Codes: Secure Device Pairing Using Short-Range Acoustic Communication

Secure Device Pairing (SDP) relies on an out-of-band channel to authenticate devices. This requires a common hardware interface, which limits the use of existing SDP systems. We propose to use short-range acoustic communication for the initial pairing. Audio hardware is commonly available on existing off-the-shelf devices and can be accessed from user space without requiring firmware or hardware modifications. We improve upon previous approaches by designing Acoustic Integrity Codes (AICs): a modulation scheme that provides message authentication on the acoustic physical layer. We analyze their security and demonstrate that we can defend against signal cancellation attacks by designing signals with low autocorrelation. Our system can detect overshadowing attacks using a ternary decision function with a threshold. In our evaluation of this SDP scheme's security and robustness, we achieve a bit error ratio below 0.1% for a net bit rate of 100 bps with a signal-to-noise ratio (SNR) of 14 dB. Using our open-source proof-of-concept implementation on Android smartphones, we demonstrate pairing between different smartphone models.Comment: 11 pages, 11 figures. Published at ACM WiSec 2020 (13th ACM Conference on Security and Privacy in Wireless and Mobile Networks). Updated reference

비가청 고주파음역을 활용한 전시가이드 시스템의 구현

학위논문 (석사)-- 서울대학교 융합과학기술대학원 : 융합과학부(디지털정보융합전공), 2014. 2. 이교구.This thesis presents a new method for exhibition guide systems, an application for mobile devices that utilizes near-ultrasonic sound waves as communication signals. This system substitutes existing museum or gallery guide systems that use technologies such as infrared sensors, QR codes, RFID, or any other manual input. In the proposed system, a near-field tweeter speaker stands near each piece of artwork and transmits mixed tones in the inaudible frequency range. The receiver application filters interfering noise and pinpoints the signal coming from the nearest artwork, identifies the artwork, and requests the corresponding information from the data server. This process is done automatically and seamlessly, requiring no input from the user. Experiments show that the method is highly accurate and robust to noise, indicating its potential applications to other areas such as indoor positioning systems. In addition, a case study shows that the proposed system is favorable in many aspects compared to existing guide systems.Chapter 1 Introduction 1.1 Background 1.2 Motivation and Objectives 1.3 Thesis Organization Chapter 2 Related Work 2.1 Mobile-Based Exhibition Guides 2.2 Methods Utilizing Near-Ultrasound 2.3 Exhibition Guide System Utilizing Near-Ultrasound Chapter 3 Research Method 3.1 Near-Ultrasound 3.2 System Configuration 3.3 Implementation Chapter 4 Experiments 4.1 Performance Test 4.1.1 Distance Experiment 4.1.2 Position Experiment 4.2 Case Study 4.2.1 Experiment Setup 4.2.2 Case Study Results Chapter 5 Discussion and Future Work Chapter 6 Conclusion Bibliography Abstract (Korean)Maste

Fuzz sensoring

Treball desenvolupat en el marc del programa "European Project Semester".Traffic congestion is a significant problem which affects smoothness in transportation in many cities around the world. It is unavoidable due to increasing numbers of vehicles and overuse of roads in large and growing metropolises. Although, there are several policies that are implemented to reduce traffic congestion, such as improvement of public transport, car and motorcycle restriction on several roads, and an even-odd license plate policy, the major problem involves getting data in order to predict and avoid traffic. Information can be collected from many sources such as: city sensors, GPS, as well as, from many application programming interfaces (API) provided by different companies. The project involves gathering sources and information about traffic congestion in order to create guidelines which can be essential in creating a traffic map of Vilanova i la Geltrú in the future. Eventually, the guidelines to the city of Vilanova i la Geltrú are provided, consisting of analysis of traffic inside the city, IoT management, choices of APIs, effective selection of sensors, and cost analysis to vastly improve traffic flow.Incomin

Vehicle Collision Avoidance System Using Li-Fi

In recent times, large numbers of road accidents occurring all over the world are mainly due to collisions between vehicles. More than 1.2 million peoples were died in road accidents in 2019, according to the World Health Organization (WHO). Human safety features are much needed in the manufacturing of vehicles. The proposed method mainly focuses on reducing the number of accidents in our daily lives by avoiding collision between the vehicles. There are several factors corresponding to such difficult conditions that may results in death or disabilities. The causes are sudden loss of concentration of the driver, braking failure and stability issues. These criteria can be reduced only if there is a possibility for communication between the vehicles and the drivers in order to avoid accidents. There are various vehicular communication system models like Dedicated Short Range Communication and Vehicular Ad-Hoc network operating less than 5.9 GHz. These radio frequency based communication also has some limitations such as interference, congested spectrum and security. These drawbacks can be reduced by implementing the Visible Light Communication (VLC) in vehicles. It provides larger bandwidth, security, interference immunity, and high data rate. High speed data transmission and reception can be achieved using visible light based data communication system. This technology is known as Light Fidelity (Li-Fi). This chapter presents the innovative method to evade collision between two vehicles (rear and front). This communication system is cost effective with high speed data rate capabilities