@conference {570, title = {Making Blockchain Validators Honest}, booktitle = {2022 Fourth International Conference on Blockchain Computing and Applications (BCCA)}, year = {2022}, abstract = {

The importance of honesty among blockchain validators can not be overemphasized, especially as blockchain is used by many as an underlying technology for the development of various Industry 4.0 solutions. In the blockchain consensus process, validators validate the correctness of transactions and propose new blocks for addition to the blockchain. They are rewarded for this task with the blockchain native token (e.g., ETH on the Ethereum blockchain). This reward is often distributed among validators with respect to their staked amount. An increasing number of validators joining the network leads to a decreasing chance of a validator being chosen for the validation task and thus a reduction in the validation reward. This situation results in some form of competition among the validators, leading them to carry out various malicious actions to influence the blockchain validator selection protocol in order to be chosen. In this paper, we examine the competitive interactions between validators in a blockchain consensus process and propose a model using an infinitely repeated game model that ensures that the validators are deterred from behaving maliciously while also encouraging a self-policing notion due to the extra incentive mechanism of an improved reputation score when a validator can verifiably report malicious activities by others. Further, we discuss the factors that can incentivize or disincentivize a validator to either continue to behave honestly or switch to dishonest behavior.

}, doi = {10.1109/BCCA55292.2022.9921952}, url = {https://ieeexplore.ieee.org/abstract/document/9921952}, author = {Salau, Abiola and Dantu, Ram and Morozov, Kirill and Badruddoja, Syed and Upadhyay, Kritagya} } @conference {575, title = {Making Smart Contracts Predict and Scale}, booktitle = {2022 Fourth International Conference on Blockchain Computing and Applications (BCCA)}, year = {2022}, abstract = {

The machine learning algorithms can predict the events based on the trained models and datasets. However, a reliable prediction requires the model to be trusted and tamper-resistant. Blockchain technology provides trusted output with consensus-based transactions and an immutable distributed ledger. The machine learning algorithms can be trained on blockchain smart contracts to produce trusted models for reliable prediction. But most smart contracts in the blockchain do not support floating-point data type, limiting computations for classification, which can affect the prediction accuracy. In this work, we propose a novel method to produce floating-point equivalent probability estimation to classify labels on-chain with a Naive Bayes algorithm. We derive a mathematical model with Taylor series expansion to compute the ratio of the posterior probability of classes to classify labels using integers. Moreover, we implemented our solution in Ethereum blockchain smart-contract with the Solidity programming language, where we achieved a prediction accuracy comparable to the scikit-learn library in Python. Our derived method is platform-agnostic and can be supported in any blockchain network. Furthermore, machine learning and deep-learning algorithms can borrow the derived method.

}, doi = {10.1109/BCCA55292.2022.9922480}, author = {Badruddoja, Syed and Dantu, Ram and He, Yanyan and Thompson, Mark and Salau, Abiola and Upadhyay, Kritagya} } @conference {572, title = {Smarter Contracts to Predict using Deep-Learning Algorithms}, booktitle = {2022 Fourth International Conference on Blockchain Computing and Applications (BCCA)}, year = {2022}, abstract = {

Deep learning techniques can predict cognitive intelligence from large datasets involving complex computations with activation functions. However, the prediction output needs verification for trust and reliability. Moreover, these algorithms suffer from the model{\textquoteright}s provenance to keep track of model updates and developments. Blockchain smart contracts provide a trustable ledger with consensus-based decisions that assure integrity and verifiability. In addition, the immutability feature of blockchain also supports the provenance of data that can help deep learning algorithms. Nevertheless, smart contract languages cannot predict due to the absence of floating-point operations required by activation functions of neural networks. In this paper, we derive a novel method using the Taylor series expansion to compute the floating-point equivalent output for activation functions. We train the deep learning model off-chain using a standard Python programming language. Moreover, we store models and predict on-chain with blockchain smart contracts to produce a trusted forecast. Our experiment and analysis achieved an accuracy (99\%) similar to popular Keras Python library models for the MNIST dataset. Furthermore, any blockchain platform can reproduce the activation function using our derived method. Last but not least, other deep learning algorithms can reuse the mathematical model to predict on-chain.

}, doi = {10.1109/BCCA55292.2022.9922240}, author = {Badruddoja, Syed and Dantu, Ram and He, Yanyan and Thompson, Mark and Salau, Abiola and Upadhyay, Kritagya} } @conference {503, title = {Towards a Threat Model and Security Analysis for Data Cooperatives}, booktitle = {19th International Conference on Security and Cryptography (SECRYPT 2022)}, year = {2022}, abstract = {

Data cooperative (called {\textquotedblleft}data coop{\textquotedblright} for short) is an emerging approach in the area of secure data management. It promises its users a better protection and control of their data, as compared to the traditional way of their handling by the data collectors (such as governments, big data companies, and others). However, for the success of data coops, existing challenges with respect to data management systems need to be adequately addressed. Especially, they concern terms of security and privacy, as well as the power imbalance between providers/owners and collectors of data. Designing a security and privacy model for a data coop requires a systematic threat modeling approach that identifies the security landscape, attack vectors, threats, and vulnerabilities, as well as the respective mitigation strategies. In this paper, we analyze the security of data cooperatives, identify potential security risks and threats, and suggest adequate countermeasures. We also discuss existing challenges that hinder the widespread adoption of data coops.\ 

}, keywords = {Cybersecurity, Data Cooperatives, Secure Data Management, Security and Privacy., Threat Model}, doi = {10.5220/0011328700003283}, author = {Salau, Abiola and Dantu, Ram and Morozov, Kirill and Upadhyay, Kritagya and Badruddoja, Syed} } @conference {565, title = {Trusted AI with Blockchain to Empower Metaverse}, booktitle = {2022 Fourth International Conference on Blockchain Computing and Applications (BCCA)}, year = {2022}, abstract = {

The digital experience emerging in the virtual world is a reality with the advent of the metaverse. Augmented reality(AR), virtual reality(VR), extended reality(XR), and artificial intelligence(AI) algorithms would pave the way for an immersive experience for the users in the virtual space. However, the explosion of these technologies broaches new challenges to threaten the success of metaverse due to security risks. The blockchain technology augmented with AI promises to deliver a trusted metaverse for everyone. Nevertheless, smart contracts fail to produce a cognitive prediction, dissuading users from confiding in the metaverse. We arm smart contracts with intelligence to predict using AI algorithms. Moreover, we deploy the smart contracts on the Ethereum blockchain platform and produce a prediction accuracy of 95\% compared to Python scikit-learn-based predictions. Our results show that the prediction delay can obstruct the growth of metaverse applications to accept blockchain technologies. Furthermore, the limitation of blockchain technology can make integration unreasonable. Therefore, we discuss possible scalability solutions that can be part of our future work to help more metaverse applications adopt blockchain solutions.

}, doi = {10.1109/BCCA55292.2022.9922027}, author = {Badruddoja, Syed and Dantu, Ram and He, Yanyan and Thompson, Mark and Salau, Abiola and Upadhyay, Kritagya} } @conference {522, title = {Can{\textquoteright}t Understand SLAs? Use the Smart Contract}, booktitle = {2021 Third IEEE International Conference on Trust, Privacy and Security in Intelligent Systems and Applications (TPS-ISA)}, year = {2021}, publisher = {IEEE}, organization = {IEEE}, address = {Atlanta, GA, USA}, abstract = {

A Service Level Agreement (SLA) is a special kind of legal contract that binds a vendor to its customers where the vendor commits to provide certain services in exchange for certain payment from the customers. On the other hand, a Smart Contract is a contract that is a computer program that also binds multiple parties into given agreements but is a set of a precise rules and is self-enforceable and self-executable. Since almost all legal contracts are ambiguous by nature and are complex to read and understand, we perform a novel study on how we can replace the traditional vague legal contract with the smart contact and the effect of the ambiguity on the smart contract by performing a thorough analysis on SLAs by measuring their ambiguities in various aspects. We take several samples of real SLAs from six different popular broadband vendors. We use four random SLAs to train the machine learning model to classify and then detect ambiguous words in two unseen SLAs which were the SLAs of Ziply Fiber and Century Link. As different people form different interpretations while reading the ambiguous legal contracts, we generate various human interpretations from the machine detected ambiguous words and convert all those generated interpretations into Smart Contracts to perform testing in Ethereum-based Blockchain to identify the most ambiguous as well as accurate interpretation of the SLA. From our analysis and observation, we were able to find out the most ambiguous interpretation of SLAs and we concluded that the SLA of Ziply Fiber was more ambiguous in general compared to the SLA of Century Link. Moreover, our proposed approach to detect ambiguous terms and to translate an ambiguous legal contract to a smart legal contract using a formal language to measure the degree of ambiguity can be extrapolated and replicated to legal contracts from other types of industries as well.

}, keywords = {ambiguity, ambiguity index, blockchain, clauses, complexity, Ethereum, interpretations, machine learning, service level agreement, SLA, smart contract, smart legal contract}, isbn = {978-1-6654-1623-8}, doi = {10.1109/TPSISA52974.2021.00015}, url = {https://ieeexplore.ieee.org/abstract/document/9750250}, author = {Upadhyay, Kritagya and Dantu, Ram and He, Yanyan and Badruddoja, Syed and Salau, Abiola} } @conference {528, title = {Data Cooperatives for Neighborhood Watch}, booktitle = {2021 IEEE International Conference on Blockchain and Cryptocurrency (ICBC)}, year = {2021}, publisher = {IEEE}, organization = {IEEE}, address = {Sydney, Australia}, abstract = {

The increasing proliferation of user data is moving the world from the era of {\textquoteright}big data{\textquoteright} to a new era of shared data, and some are considering data as a factor of production that is paving the way for a new business economy. In this paper, we propose a solution that uses blockchain technology as a platform for online neighborhood watch using a form of data cooperative among individuals or organizations in the sharing of data through a peer-to-peer mechanism. We prove the concept by implementing a distributed phishing data sharing system that will maintain a community ledger of reported phishing activities with a consensus-based approval of the phishing transaction and a novel reputation scoring system thereby adding reliability to the system and effectively tackling the phishing problem. The data cooperative provides a way for timely multi-party sharing of phishing data among anti-phishing organizations and users of the internet eliminating the current approach of each organization maintaining its database. Our results show that blockchain is effective in complementing the existing methods of phishing detection and serves as a platform for sharing phishing data with respect to scalability, cost, and memory consumption. Also, our results further show that transaction times on the Ropsten test net follow a Gamma distribution. Our approach can be extrapolated to other data sharing systems like medical data, spam calls, discussion forums, etc.

}, keywords = {blockchain, Cybersecurity, data cooperative, data sharing, distributed ledger, peer-to- peer, phishing, smart contract}, isbn = {978-1-6654-3578-9}, doi = {10.1109/ICBC51069.2021.9461056}, url = {https://ieeexplore.ieee.org/abstract/document/9461056}, author = {Salau, Abiola and Dantu, Ram and Upadhyay, Kritagya} } @conference {513, title = {Make Consumers Happy by Defuzzifying the Service Level Agreements}, booktitle = {2021 Third IEEE International Conference on Trust, Privacy and Security in Intelligent Systems and Applications (TPS-ISA)}, year = {2021}, publisher = {IEEE}, organization = {IEEE}, address = {Atlanta, GA, USA}, abstract = {

A Service Level Agreement (SLA) is a special kind of legal contract that binds a vendor to its customers where the vendor commits to provide certain services in exchange for certain payments from the customers. However, when customers do not get the services that they have subscribed for, it becomes a laborious job for customers to contact or visit the company and claim the correct amount of compensation or service credits. On the other hand, a Smart Contract is a contract that is a computer program that also binds multiple parties into given agreements but is a set of precise rules and is self-enforceable and self-executable. In this paper, we have introduced a novel work where we use fuzzy logic inside the Ethereum-based smart contract for two significant objectives. The first objective is to make the claim of the compensation easier and faster for customers by translating the SLA into a smart contract. The second objective is to make the smart contract even smarter and intelligent by implementing fuzzy logic so that customers who have a hard time understanding the legal jargon and ambiguities of the legal contract and SLA to find out if the compensation amount they are getting when the service is poor is good enough. Since fuzzy logic models semantics of linguistic expressions by capturing vagueness in the fuzzy sets, it becomes easier to solve the problem of contractual ambiguities and expedite the process of claiming compensation when implemented in a Blockchain-based smart contract.

}, keywords = {ambiguity, blockchain, clauses, complexity, Ethereum, Fuzzy logic, interpretations, service level agreement, SLA, smart contract, smart legal contract}, isbn = {978-1-6654-1623-8}, doi = {10.1109/TPSISA52974.2021.00011}, url = {https://ieeexplore.ieee.org/abstract/document/9750258}, author = {Upadhyay, Kritagya and Dantu, Ram and He, Yanyan and Salau, Abiola and Badruddoja, Syed} } @conference {518, title = {Paradigm Shift from Paper Contracts to Smart Contracts}, booktitle = {2021 Third IEEE International Conference on Trust, Privacy and Security in Intelligent Systems and Applications (TPS-ISA)}, year = {2021}, publisher = {IEEE}, organization = {IEEE}, address = {Atlanta, GA, USA}, abstract = {

The ambiguity and complexity of the traditional legal contracts have motivated the study and exploration of a better and advanced contract known as blockchain-based smart contracts. A smart contract is a self-executable contract where the terms of the agreement between the involved parties are directly written into the lines of code that resides in the distributed ledger technology known as the blockchain. Obtaining a better understanding of smart contracts to overcome the fundamental issues of traditional legal contracts is vital for the successful and faster dispute settlement process without the intervention of any third-party mediators like courts, banks, lawyers, etc. In this paper, we present a comprehensive overview of the key features of the paradigm shift from traditional paper contracts to smart contracts. In addition, we also discuss why smart contracts are necessary to be legally enforced and the crucial conditions that are required for them to be legally enforceable. Furthermore, we outline recent trends and emerging technologies such as Natural Language Processing, Machine Learning, and the Internet of Things that have been combined together with smart contracts.

}, keywords = {ambiguity, artificial intelligence, blockchain, electronic contract, enforceability, Ethereum, interpretations, smart contract, traditional legal contract}, isbn = {978-1-6654-1623-8}, doi = {10.1109/TPSISA52974.2021.00029}, url = {https://ieeexplore.ieee.org/abstract/document/9750226}, author = {Upadhyay, Kritagya and Dantu, Ram and He, Yanyan and Salau, Abiola and Badruddoja, Syed} } @article {300, title = {A novel heart-mobile interface for detection and classification of heart sounds}, journal = {Biomedical Signal Processing and Control}, volume = {45}, year = {2018}, pages = {313 - 324}, abstract = {

Abstract Diagnosis of heart disease requires that a medical practitioner investigate heart auscultations for irregular sounds, followed by echocardiography and electrocardiography tests. These expensive tests also require specialized technicians to operate. We present a low-cost, patient-centered device for the initial screening of the heart sounds that can be potentially used by the users on themselves. They can later share these readings with their healthcare providers. We have created an innovative mobile-health service platform for analyzing and classifying heart sounds. The presented system enables remote patient-monitoring by integrating advanced wireless communications with a customized low-cost stethoscope. This system also permits remote management of a patient{\textquoteright}s cardiac status while maximizing patient mobility. The smartphone application facilitates recording, processing, visualizing, listening to, and classification of heart sounds. We build our classification model using the Mel-Frequency Cepstral Coefficient and Hidden Markov Model. This application is tested in a hospital environment to collect live recordings from patients with positive results. The smartphone application correctly detected 92.68\% of abnormal heart conditions in clinical trials at \{UT\} Southwestern Hospital.

}, keywords = {Hidden Markov Model}, issn = {1746-8094}, doi = {https://doi.org/10.1016/j.bspc.2018.05.008}, url = {https://www.sciencedirect.com/science/article/pii/S1746809418301101}, author = {Thiyagaraja, Shanti and Ram Dantu and Shrestha, Pradhumna and Chitnis, Anurag and Thompson, Mark and Anumandla, Pruthvi and Sarma, Tom and Dantu, Siva} } @conference {310, title = {An OAuth-Based Authorization Framework for Access Control in Remote Collaboration Systems}, booktitle = {National Cyber Summit}, year = {2018}, month = {06/2018}, address = {Huntsville, Alabama, USA}, abstract = {

Advanced human computer interaction systems have made it possible for helpers (professionals) to remotely collaborate with workers (individuals seeking assistance from the professionals). For example, a professional can remotely help a worker fix automobiles or electronics, identify how much of what medication to take, or perform household repairs. We have presented a system, Collaborative Appliance for Remote-help (CARE) that allows for such collaborations. Our system allows a skilled professional or other helper to remotely access and control a worker{\textquoteright}s locally deployed resources over the Internet. These locally deployed resources may include cameras, microphones, speakers, processors, and memory. The remote helper then directs the worker to perform specific tasks to complete the job at hand. Like other Internet of Things (IoT) based systems, CARE is inputconstrained. That is, a worker cannot provide input via a touch screen or keyboard.

The resources are accessed over the Internet. Thus, security and privacy are big concerns. In this paper, we present the authorization and access control framework for the inputconstrained CARE system. This framework has been implemented using the OAuth 2.0 Authorization Framework and has been designed to meet the needs of resource owners who have no technical knowledge. We have shown that our proposed framework is very effective and consistent with the access control guidelines set by the National Institute of Standards and Technology (NIST).

}, author = {Jonnada, Srikanth and Ram Dantu and Shrestha, Pradhumna and Ranasinghe, Ishan and Widick, Logan} } @conference {382, title = {Performance Analysis of Elliptic Curves for Real-Time Video Encryption}, booktitle = {2018 National Cyber Summit (NCS)}, year = {2018}, month = {June}, abstract = {

The use of real-time video streaming is increasing day-by-day, and its security has become a serious issue now. Video encryption is a challenging task because of its large frame size. Video encryption can be done with symmetric key as well as asymmetric key encryption. Among different asymmetric key encryption technique, ECC performs better than other algorithms like RSA in terms of smaller key size and faster encryption and decryption operation. In this work, we have analyzed the performance of 18 different ECC curves and suggested some suitable curves for real-time video encryption.

}, keywords = {Delays, ECC, Elliptic curve cryptography, encryption, Jitter, real-time systems, Real-time video streaming, Security, Streaming media}, doi = {10.1109/NCS.2018.00015}, author = {Sen, Nilanjan and Ram Dantu and Vempati, Jagannadh and Thompson, Mark} } @article {388, title = {On the security of the Courtois-Finiasz-Sendrier signature}, year = {2018}, isbn = {23915455}, url = {https://www.degruyter.com/view/j/math.2018.16.issue-1/math-2018-0011/math-2018-0011.xml}, author = {Morozov, Kirill and Sarathi, Roy Partha and Rainer, Steinwandt and Rui, Xu} } @conference {262, title = {Optimized and Secured Transmission and Retrieval of Vital Signs from Remote Devices}, booktitle = {2017 IEEE/ACM International Conference on Connected Health: Applications, Systems and Engineering Technologies (CHASE)}, year = {2017}, month = {July}, abstract = {

Smartphones and other mobile platforms provide a low cost and easily accessible method of monitoring patient health, and aid healthcare professionals in early detection of disease. Immediate access to the gathered data is an essential factor in effective patient care. But the current processes used for patients{\textquoteright} vital data collection is slow and error prone. This undermines the advantages of remote monitoring that mobile platforms for health monitoring provide. In this paper, we propose to upload the patient health information to the Cloud. We investigate three different models to transfer data from the smartphone to the Cloud-perform all computations in the smartphone, perform all computations in the Cloud, and divide the computations between the smartphone and the Cloud. The second approach was found to be infeasible due to very high latency in data transfer with a delay of 2.84 seconds at an upload speed of 2500 KBytes per second. In order to protect the privacy of patients, it is required by law that the data gathered from remote monitoring by using mobile platforms must be kept private, and be secured before uploading to the Cloud. This paper explores the use of prominent public key encryption algorithms and their performance on a mobile device to securely transmit confidential electronic personal health information to the Cloud. We analyze performance of three common public key encryption schemes -RSA, Diffie-Hellman, and ECC. It is shown that 160 bit key size in ECC scheme provides the same level of security that a 1024 bit key size does in RSA and Diffie-Hellman. Further, the encryption and decryption time required by ECC is three times less than the other two schemes. Hence, ECC not only requires a smaller key size to provide the same level of security, but also faster encryption and decryption times as compared to the other two schemes. This makes ECC algorithms suitable to be implemented in resource constrained mobile platforms. We also compared ECC curves from three different standards - NIST, SECG, and Brainpool - to determine the optimum ECC curve, and key size to encrypt data in the mobile phone platform. It is shown that the Brainpool curve performed better than the other two standards when the key size is less than 521 bits. We also measured the latency of uploading encrypted data in a wide variety of WiFi and mobile networks.

}, keywords = {Brainpool curve, Cloud computing, confidential electronic personal health information, data transfer, decryption, Diffie-Hellman, Diseases, ECC algorithms, ECC curves, encryption, error prone, health care, healthcare professionals, Mobile communication, mobile device, mobile health, mobile networks, mobile phone platform, patient care, patient health information, patient health monitoring, patient vital data collection, Performance evaluation, public key cryptography, public key encryption algorithms, remote devices, remote monitoring, resource constrained mobile platforms, RSA, secured transmission, Security, servers, smart phones, smartphones, vital signs, WiFi}, doi = {10.1109/CHASE.2017.55}, author = {Thiyagaraja, Shanti and Ram Dantu and Shrestha, Pradhumna and Thompson, Mark and Smith, Christopher} } @article {261, title = {Real-Time Mobile Device-Assisted Chest Compression During Cardiopulmonary Resuscitation}, journal = {American Journal of Cardiology}, volume = {120}, year = {2017}, pages = {196 - 200}, isbn = {0002-9149}, url = {http://dx.doi.org/10.1016/j.amjcard.2017.04.007}, author = {Sarma, Satyam and Bucuti, Hakiza and Chitnis, Anurag and Klacman, Alex and Ram Dantu} } @conference {216, title = {Smart phone monitoring of second heart sound split}, booktitle = {2014 36th Annual International Conference of the IEEE Engineering in Medicine and Biology Society}, year = {2014}, month = {Aug}, abstract = {

Heart Auscultation (listening to heart sounds) is the basic element of cardiac diagnosis. The interpretation of these sounds is a difficult skill to acquire. In this work we have developed an application to detect, monitor, and analyze the split in second heart sound (S2) using a smart phone. The application records the heartbeat using a stethoscope connected to the smart phone. The audio signal is converted into the frequency domain using Fast Fourier Transform to detect the first and second heart sounds (S1 and S2). S2 is extracted and fed into the Discrete Wavelet Transform (DWT) and then to Continuous Wavelet Transform (CWT) to detect the Aortic (A2) and the Pulmonic (P2) components, which are used to calculate the split in S2. With our application, users can continuously monitor their second heart sound irrespective of ages and check for a split in their hearts with a low-cost, easily available equipment.

}, keywords = {acoustic signal processing, aortic component, biomedical equipment, Biomedical monitoring, cardiac diagnosis, cardiology, continuous wavelet transform, Continuous wavelet transforms, discrete wavelet transform, discrete wavelet transforms, fast Fourier transform, fast Fourier transforms, frequency domain, Heart, heart auscultation, heartbeat recording, medical signal processing, Monitoring, patient diagnosis, patient monitoring, pulmonic component, second heart sound split, smart phone monitoring, smart phones, stethoscope}, doi = {10.1109/EMBC.2014.6944050}, author = {Thiyagaraja, Shanti and Vempati, Jagannadh and Ram Dantu and Sarma, Tom and Dantu, Siva} } @article {15, title = {Cuffless Differential Blood Pressure Estimation Using Smart Phones}, journal = {IEEE Transactions on Biomedical Engineering}, volume = {60}, year = {2013}, pages = {1080 - 1089}, abstract = {

Smart phones today have become increasingly popular with the general public for their diverse functionalities such as navigation, social networking, and multimedia facilities. These phones are equipped with high-end processors, high-resolution cameras, and built-in sensors such as accelerometer, orientation-sensor, and light-sensor. According to comScore survey, 26.2\% of U.S. adults use smart phones in their daily lives. Motivated by this statistic and the diverse capability of smart phones, we focus on utilizing them for biomedical applications. We present a new application of the smart phone with its built-in camera and microphone replacing the traditional stethoscope and cuff-based measurement technique, to quantify vital signs such as heart rate and blood pressure. We propose two differential blood pressure estimating techniques using the heartbeat and pulse data. The first method uses two smart phones whereas the second method replaces one of the phones with a customized external microphone. We estimate the systolic and diastolic pressure in the two techniques by computing the pulse pressure and the stroke volume from the data recorded. By comparing the estimated blood pressure values with those measured using a commercial blood pressure meter, we obtained encouraging results of 95{\textendash}100\% accuracy.

}, keywords = {Blood pressure, cuffless, Estimation, finger pulse, Heart, Microphones, mobile camera, Mobile communication, mobile phone, Synchronization, Valves, vascular transit time}, doi = {10.1109/TBME.2012.2211078}, author = {Chandrasekaran, Vikram and Ram Dantu and Jonnada, Srikanth and Thiyagaraja, Shanti and Subbu, Kalyan} } @article {25, title = {LocateMe: Magnetic-fields-based Indoor Localization Using Smartphones}, journal = {ACM Trans. Intell. Syst. Technol.}, volume = {4}, year = {2013}, pages = {73:1{\textendash}73:27}, abstract = {

Fine-grained localization is extremely important to accurately locate a user indoors. Although innovative solutions have already been proposed, there is no solution that is universally accepted, easily implemented, user centric, and, most importantly, works in the absence of GSM coverage or WiFi availability. The advent of sensor rich smartphones has paved a way to develop a solution that can cater to these requirements.

By employing a smartphone{\textquoteright}s built-in magnetic field sensor, magnetic signatures were collected inside buildings. These signatures displayed a uniqueness in their patterns due to the presence of different kinds of pillars, doors, elevators, etc., that consist of ferromagnetic materials like steel or iron. We theoretically analyze the cause of this uniqueness and then present an indoor localization solution by classifying signatures based on their patterns. However, to account for user walking speed variations so as to provide an application usable to a variety of users, we follow a dynamic time-warping-based approach that is known to work on similar signals irrespective of their variations in the time axis.

Our approach resulted in localization distances of approximately 2m--6m with accuracies between 80--100\% implying that it is sufficient to walk short distances across hallways to be located by the smartphone. The implementation of the application on different smartphones yielded response times of less than five secs, thereby validating the feasibility of our approach and making it a viable solution.

}, keywords = {Indoor localization, Magnetic fields, smartphones, ubiquitous}, issn = {2157-6904}, doi = {10.1145/2508037.2508054}, url = {http://doi.acm.org/10.1145/2508037.2508054}, author = {Subbu, Kalyan and Gozick, Brandon and Ram Dantu} } @article {82, title = {Socio-technical Aspects of Remote Media Control for a NG9-1-1 System}, journal = {Multimedia Tools Appl.}, volume = {62}, year = {2013}, pages = {733{\textendash}759}, abstract = {

9-1-1 emergency calls mostly involve distress situations that cause people to panic while trying to answer questions or follow instructions given by a dispatcher. To obtain precious information with the least user intervention and reduced stress on the user, there is a need for the dispatcher to have a better control and understanding of the condition or situation at the other end. The increasing growth of smartphones embedded with camera, speaker phone, GPS, microphone and various other sensors, extends their usage from merely making calls to life saving gadgets during critical situations. By integrating these sensor rich smartphones and the rapidly growing VoIP technology, we propose a VoIP based Next Generation 9-1-1 (NG9-1-1) system for remote media control. Specifically, we use Session Initiation Protocol (SIP) in the implementation of the system using a mobile and a PC client. The proposed system on the mobile client accounted for less than 25\% of CPU utilization even with video transmission. The average network utilization was about 10 and 72 kbps for audio and video, respectively. With these encouraging results, we believe the proposed remote media control system will facilitate information acquisition and decision making in emergency situations.

}, keywords = {Image transmission, Media control, NG9-1-1, PSAP, Remote, SIP, Voice quality, VoIP}, issn = {1380-7501}, doi = {10.1007/s11042-011-0875-1}, url = {http://dx.doi.org/10.1007/s11042-011-0875-1}, author = {Chandrasekaran, Vikram and Ram Dantu and Subbu, Kalyan} } @conference {21, title = {Evaluation of gyroscope-embedded mobile phones}, booktitle = {Systems, Man, and Cybernetics (SMC), 2011 IEEE International Conference on}, year = {2011}, address = {Anchorage, AK}, abstract = {

Many mobile phone applications such as pedometers and navigation systems rely on orientation sensors that most smartphones are now equipped with. Unfortunately, these sensors rely on measured accelerometer and magnetic field data to determine the orientation. Thus, accelerations upon the phone which arise from everyday use alter orientation information. Similarly, external magnetic interferences from indoor/urban settings affect the heading calculation, resulting in inaccurate directional information. The inability to determine the orientation during everyday use inhibits many potential mobile applications development. In this work, we exploit the newly built-in gyroscope in the Nexus S smartphone to address the interference problems associated with the orientation sensor. We first perform drift error analysis and apply this to gyroscope calculations. We test simple as well as complex rotations seen in walking applications. We lastly test the gyroscope{\textquoteright}s resistance to described interferences. Experiments show angular calculations with percent error no larger than 6\% from actual rotated values. Further, we are able to determine the phone{\textquoteright}s orientation at any time, in magnetically-interfered areas, with the phone accelerating. With this accurate information we can virtually orient the phone to better use mobile-acquired data. This shows that the presence of a gyroscope in smartphones will certainly aid in numerous applications.

}, keywords = {Acceleration, Accelerometer, Accelerometers, Angular rotation, Gyroscope, Gyroscopes, Magnetic sensors, Mobile communication, Mobile handsets, mobile phone, Orientation sensor}, isbn = {978-1-4577-0652-3}, doi = {10.1109/ICSMC.2011.6083905}, author = {Barthold, Christopher and Subbu, Kalyan and Ram Dantu} } @conference {36, title = {Indoor localization through dynamic time warping}, booktitle = {2011 IEEE International Conference on Systems, Man, and Cybernetics}, year = {2011}, month = {10/2011}, address = {Anchorage, AK}, abstract = {

Identifying and locating oneself in different hallways of high rise buildings forms the classic indoor localization problem. GPS does not work indoors and WiFi may not be omnipresent. This paper presents a novel approach to ambient magnetic fields based indoor localization. We present a system that classifies magnetic signatures using dynamic time warping. Specifically, by aligning similar magnetic signatures that differ in magnitude or time, we classify the signatures and infer the location irrepective of the person and his/her mode of commuting. A Nexus One smartphone was employed, utilizing its builtin magnetic field sensor to create a user friendly localization application solely on the phone. By using a variety of subjects including sighted, blindfolded and people using wheelchairs to handle the human speed variation problem, we evaluated the system across 26 and 15 hallways of two different buildings and obtained accuracies of 92.6\%, and 91.1\% respectively. With these encouraging results, we believe our proposed solution is user independent and caters to a wide range of hallways.

}, keywords = {Accuracy, Buildings, Databases, Human, Humans, Legged locomotion, Localization, Magnetometers, mobile phones, sensors, Wheelchairs}, doi = {10.1109/ICSMC.2011.6083906}, author = {Subbu, Kalyan and Gozick, Brandon and Ram Dantu} } @article {9, title = {Magnetic Maps for Indoor Navigation}, journal = {IEEE Transactions on Instrumentation and Measurement}, volume = {60}, year = {2011}, pages = {3883 - 3891}, abstract = {

Magnetic field fluctuations and anomalies inside buildings tend to have a great effect on the compass, which is one of the simplest navigation devices. Alternative navigation requires landmark identification, so those landmarks can be used as guideposts in assisting individuals. By employing a mobile phone with built\_in magnetometer, an extensive data set of 2000 measurements was collected. Using these fields, we identify landmarks and guideposts and create magnetic maps for multiple corridors of a floor in a building. Different phones are used at different sensitivity rates, which effectively portray similar results. Magnetic signatures are used for identifying locations and rooms and are independent of the person, the phone, and the sensitivity of the sensor being used. Magnetic field behavior is demonstrated and compared with theoretical distributions of these fields. The developed magnetic maps can complement existing visual maps for location tracking and navigation of autonomous robots indoors. These maps are particularly useful during limited visual feedback in poor lighting conditions. Moreover, building designers could include this landmark and guidepost information when developing the architecture of a building, which could in turn help people or robots navigate during disasters and emergency evacuations.

}, keywords = {Buildings, Magnetic field measurement, Magnetic field measurements, Magnetic fields, Magnetometers, Mobile handsets, mobile phones, Navigation, sensors, Uncertainty}, doi = {10.1109/TIM.2011.2147690}, author = {Gozick, Brandon and Subbu, Kalyan and Ram Dantu and Maeshiro, Tomyo} } @inbook {54, title = {Email Shape Analysis}, booktitle = {Distributed Computing and Networking: 11th International Conference, ICDCN 2010, Kolkata, India, January 3-6, 2010. Proceedings}, year = {2010}, pages = {18{\textendash}29}, publisher = {Springer Berlin Heidelberg}, organization = {Springer Berlin Heidelberg}, address = {Berlin, Heidelberg}, abstract = {

Email has become an integral part of everyday life. Without a second thought we receive bills, bank statements, and sales promotions all to our inbox. Each email has hidden features that can be extracted. In this paper, we present a new mechanism to characterize an email without using content or context called Email Shape Analysis. We explore the applications of the email shape by carrying out a case study; botnet detection and two possible applications: spam filtering, and social-context based finger printing. Our in-depth analysis of botnet detection leads to very high accuracy of tracing templates and spam campaigns. However, when it comes to spam filtering we do not propose new method but rather a complementing method to the already high accuracy Bayesian spam filter. We also look at its ability to classify individual senders in personal email inbox{\textquoteright}s.

}, isbn = {978-3-642-11322-2}, doi = {10.1007/978-3-642-11322-2_7}, url = {http://dx.doi.org/10.1007/978-3-642-11322-2_7}, author = {Sroufe, Paul and Phithakkitnukoon, Santi and Ram Dantu and Cangussu, Jo{\~a}o}, editor = {Kant, Krishna and Pemmaraju, Sriram V. and Sivalingam, Krishna M. and Wu, Jie} } @article {72, title = {Experiences During a Collegiate Cyber Defense Competition}, journal = {Journal of Applied Security Research}, volume = {5}, year = {2010}, pages = {382{\textendash}396}, abstract = {

The objective of this article is to encourage schools to participate in the Collegiate Cyber Defense Competition (CCDC) and to ease their entry by providing information about the event and describing the experiences of both the student participants and the educators. This article focuses mainly on the recent experience of a University of North Texas student team at the Southwest Regional CCDC 2008 hosted by Del Mar College in Corpus Christi, Texas. It describes the entire process of participating in the CCDC, including announcements, team formation, task assignments, preparations, and actual team experience during the competition and provides suggestions on strategies for future competitions

}, keywords = {Cyber defense competition, network configurations, operating systems, servers}, author = {Sroufe, Paul and Tate, Steve and Ram Dantu and Cankaya, Ebru} } @article {63, title = {Next generation 9-1-1: Architecture and challenges in realizing an IP-multimedia-based emergency service}, journal = {Journal of Homeland Security and Emergency Management}, volume = {7}, year = {2010}, abstract = {

Next generation 9-1-1 (NG-9-1-1) services will enable the use of multimedia (voice, video, text messages, and data) for emergency communications. This will be made possible using a whole new architecture for emergency communications, one that is based on the internet protocol (IP) and open standards. VOIP based communication services vastly improve the effectiveness of relief during mass disasters, as was observed during Katrina. However, delivering the latest multimedia technology to Public Service Answering Points (PSAPs) presents both new opportunities and challenges. In this paper, we review how technology is evolving towards an NG-9-1-1 solution and underscore the challenges and issues that still require investigation.

}, author = {Gupta, Neeraj and Ram Dantu and Schulzrinne, Henning and Goulart, Anna and Magnussen, Walt} } @inbook {77, title = {Small World VoIP}, booktitle = {Mobile Computing, Applications, and Services: Second International ICST Conference, MobiCASE 2010, Santa Clara, CA, USA, October 25-28, 2010, Revised Selected Papers}, year = {2010}, pages = {137{\textendash}155}, publisher = {Springer Berlin Heidelberg}, organization = {Springer Berlin Heidelberg}, address = {Berlin, Heidelberg}, abstract = {

We present the analysis and design of a Small World VoIP system (SW-VoIP) which is geared towards customers that are communicating with their Small World of social contacts. We use the term Small World to refer to the Peer-to-Peer (P2P) network of a client and his contacts both incoming and outbound. We reconstruct the small world of a user by collecting calling patterns over a configurable period of time. We enable user mobility by using a stepwise social identity to an IP address binding propagation model. We propose an efficient algorithm to locate users by electing popular users and leveraging the users closeness. We also introduce a self-stabilized load balancing mechanism to optimize the system performance under heavy network traffic. We evaluate our SW-VoIP system performance by simulating the user{\textquoteright}s lookup process using real-world telephone logs. Our experimental results show that our SW-VoIP system offers a better performance in optimizing the required routing path and reducing the average lookup delay when compared to traditional, non small-world P2P VoIP systems.

}, keywords = {closeness, electing, mobility, optimize, Peer-to-peer, popular, small world, VoIP}, isbn = {978-3-642-29336-8}, doi = {10.1007/978-3-642-29336-8_8}, url = {http://dx.doi.org/10.1007/978-3-642-29336-8_8}, author = {Yang, Xiaohui and Stavrou, Angelos and Ram Dantu and Wijesekera, Duminda}, editor = {Gris, Martin and Yang, Guang} } @conference {29, title = {Email Shape Analysis for Spam Botnet Detection}, booktitle = {Proceedings of the 6th IEEE Conference on Consumer Communications and Networking Conference}, year = {2009}, publisher = {IEEE Press}, organization = {IEEE Press}, address = {Piscataway, NJ, USA}, abstract = {

Botnets have become the major sources of spamming, which generates massive unwanted traffic on networks. An effective detection mechanism can greatly mitigate the problem. In this paper, we present a novel botnet detection mechanism based on the email "shape" analysis that relies on neither content nor reputation analysis. Shape is our new way of characterizing an email by mimicking human visual inspection. A set of email shapes are derived and then used to generate a botnet signature. Our preliminary results show greater than 80\% classification accuracy (without considering email content or reputation analysis). This work investigates the discriminatory power of email shape, for which we believe will be a significant complement to other existing techniques such as a network behavior analysis.

}, isbn = {978-1-4244-2308-8}, url = {http://dl.acm.org/citation.cfm?id=1700527.1700792}, author = {Sroufe, Paul and Phithakkitnukoon, Santi and Ram Dantu and Cangussu, Jo{\~a}o} } @conference {69, title = {iKnow Where You Are}, booktitle = {Proceedings of the 2009 International Conference on Computational Science and Engineering - Volume 04}, year = {2009}, publisher = {IEEE Computer Society}, organization = {IEEE Computer Society}, address = {Washington, DC, USA}, isbn = {978-0-7695-3823-5}, doi = {10.1109/CSE.2009.55}, url = {http://dx.doi.org/10.1109/CSE.2009.55}, author = {Subbu, Kalyan and Xu, Ning and Ram Dantu} } @article {16, title = {Issues and challenges in securing VoIP}, journal = {Computers \& Security}, volume = {28}, year = {2009}, pages = {743-753}, abstract = {

Voice over the Internet protocol (VoIP) is being rapidly deployed, and the convergence of the voice and data worlds is introducing exciting opportunities. Lower cost and greater flexibility are the key factors luring enterprises to transition to VoIP. Some security problems may surface with the widespread deployment of VoIP. In this article, we discuss these security problems and propose a high-level security architecture that captures required features at each boundary-network-element in the VoIP infrastructure. We describe mechanisms to efficiently integrate information between distributed security components in the architecture.

}, keywords = {Feedback, Security solutions, Threats, VoIP attacks, VoIP security}, doi = {10.1016/j.cose.2009.05.003}, author = {Ram Dantu and Fahmy, Sonia and Schulzrinne, Henning and Cangussu, Jo{\~a}o} } @inbook {46, title = {Behavioral Entropy of a Cellular Phone User}, booktitle = {Social Computing, Behavioral Modeling, and Prediction}, year = {2008}, pages = {160{\textendash}167}, publisher = {Springer US}, organization = {Springer US}, address = {Boston, MA}, abstract = {

The increase of advanced service offered by cellular networks draws lots of interest from researchers to study the networks and phone user behavior. With the evolution of Voice over IP, cellular phone usage is expected to increase exponentially. In this paper, we analyze the behavior of cellular phone users and identify behavior signatures based on their calling patterns. We quantify and infer the relationship of a person{\textquoteright}s randomness levels using information entropy based on the location of the user, time of the call, inter-connected time, and duration of the call. We use real-life call logs of 94 mobile phone users collected at MIT by the Reality Mining Project group for a period of nine months. We are able to capture the user{\textquoteright}s calling behavior on various parameters and interesting relationship between randomness levels in individual{\textquoteright}s life and calling pattern using correlation coeffi- cients and factor analysis. This study extends our understanding of cellular phone user behavior and characterizes cellular phone users in forms of randomness level.

}, isbn = {978-0-387-77672-9}, doi = {10.1007/978-0-387-77672-9_18}, url = {http://dx.doi.org/10.1007/978-0-387-77672-9_18}, author = {Phithakkitnukoon, Santi and Husna, Husain and Ram Dantu}, editor = {Liu, Huan and Salerno, John J. and Young, Michael J.} } @conference {90, title = {Experiences in building a multi-university testbed for research in multimedia communications}, booktitle = {Parallel and Distributed Processing, 2008. IPDPS 2008. IEEE International Symposium on}, year = {2008}, month = {April}, abstract = {

The next generation Internet needs to support multimedia services such as voice/video over IP (VoIP) and IP-based television (IPTV) and media distribution. The goal of the project is to develop a testbed for understanding and analysis of vulnerabilities of IP-based multimedia networks. This is a collaborative project between University of North Texas, Columbia University, Purdue University, and University of California at Davis. This project was awarded in 2006 and in one year, we have developed a multi-university testbed with variety of PBX solutions including Asterisk, a multitude of voice and video IP phones, and multiple universities were connected through a secure VPN and Internet!. As with any endeavor, experiences and we have many unique issues, which sometimes cause setbacks. We have dealt with issues concerning interoperability between phones and servers, network address translation (NAT) connectivity issues, and many other collaboration issues concerning people and technology. An interworking of students from multiple universities, faculty, system administrators and support personnel has brought the testbed resources together for a working environment. In this paper we described our progress and experiences in more detail and how to fulfill our mission statement while supporting the various collaborative efforts involved with this project. In addition, we described the current research activities based on the testbed. Finally we described the next steps in the testbed development.

}, keywords = {Asterisk, Collaboration, Collaborative work, digital television, Internet telephony, IP-based television, IPTV, media distribution, Multimedia communication, Multimedia communications, multiuniversity testbed, Network address translation, network address translation connectivity issues, Network servers, next generation Internet, open systems, PBX solutions, phones-servers interoperability, private telephone exchanges, Testing, TV, video IP phones, video over IP, virtual private network, virtual private networks, voice over IP, Web and internet services}, doi = {10.1109/IPDPS.2008.4536392}, author = {Ram Dantu and Schulzrinne, Henning and Sroufe, Paul} } @article {180, title = {Securing voice over IP}, journal = {IEEE Network}, volume = {20}, year = {2006}, month = {Sept}, pages = {4-5}, keywords = {Authentication, Fingerprint recognition, information filtering, information filters, Information security, Internet telephony, Markup languages, Protection, Protocols, Standardization}, issn = {0890-8044}, doi = {10.1109/MNET.2006.1705876}, author = {Ram Dantu and Ghosal, Dipak and Schulzrinne, Henning} } @conference {33, title = {Securing VoIP and PSTN from integrated signaling network vulnerabilities}, booktitle = {1st IEEE Workshop on VoIP Management and Security, 2006.}, year = {2006}, abstract = {

The liberalization of public switched telephone network (PSTN) and growing acceptance of SIGTRAN protocol suite have introduced new and yet to be trusted signaling entities. Thus security threats emerging from one network not only affects itself but other network also. We show how this integrated signaling environment can become a security threat to emerging VoIP and PSTN networks. We propose a security solution as a fix. Our proposal goes beyond "Gateway Screening" and "SS7 Gatekeeper" proposed by Telcordia and Verizon respectively to defend vulnerable SS7 network.

}, keywords = {Information security, Information systems, Internet telephony, IP networks, ISDN, National security, Protocols, Routing, Signal processing, Switching circuits}, doi = {10.1109/VOIPMS.2006.1638116}, author = {Sengar, Hemant and Ram Dantu and Wijesekera, Duminda} } @article {39, title = {SS7 over IP: signaling interworking vulnerabilities}, journal = {IEEE Network}, volume = {20}, year = {2006}, month = {Nov}, pages = {32-41}, abstract = {

Public telephony - the preferred choice for two-way voice communication over a long time - has enjoyed remarkable popularity for providing acceptable voice quality with negligible connection delays, perhaps due to its circuit-switched heritage. Recently, IP telephony, a packet-based telephone service that runs as an application over the IP protocol, has been gaining popularity. To provide seamless interconnectivity between these two competing services, the Internet Engineering Task Force (IETF) has designed a signaling interface commonly referred to as SIGTRAN. This seamless intersignaling provided by SIGTRAN facilitates any subscriber in one network to reach any other subscriber in the other network, passing through any heterogeneous maze of networks consisting of either of these. Unfortunately, the same intersignaling potentially can be exploited from either side to disrupt the services provided on the other side. We show how this can be done and propose a solution based on access control, signal screening, and detecting anomalous signaling. We argue that to be effective, the latter two should consider syntactic correctness, semantic validity of the signal content, and the appropriateness of a particular signal in the context of earlier exchanged messages

}, keywords = {anomalous signaling detection, circuit-switched heritage, Delay effects, Design engineering, IETF, Integrated circuit interconnections, Internet Engineering Task Force, Internet telephony, intersignaling, IP protocol, ISDN, packet-based telephone service, Protocols, public telephony, Routing, Signal detection, signal screening, signaling interworking, SIGTRAN, SS7 over IP, Switches, telecommunication signalling, two-way voice communication, Web and internet services}, issn = {0890-8044}, doi = {10.1109/MNET.2006.273119}, author = {Sengar, Hemant and Ram Dantu and Wijesekera, Duminda and Jajodia, Sushil} } @article {194, title = {Signaling System 7 (SS7) Message Transfer Part 2 (MTP2) - User Peer-to-Peer Adaptation Layer (M2PA)}, year = {2005}, author = {George, Tom and Bidulock, Brian and Ram Dantu and Schwarzbauer, Hanns and Morneault, Ken} } @article {229, title = {Requirements for Separation of IP Control and Forwarding}, year = {2003}, month = {11/2003}, publisher = {RFC Editor}, abstract = {

This document introduces the Forwarding and Control Element\ Separation (ForCES) architecture and defines a set of associated\ terminology.\  This document also defines a set of architectural,\ modeling, and protocol\ requirements to logically separate the control\ and data forwarding planes of an IP (IPv4, IPv6, etc.) networking\ device.

}, author = {Anderson, Todd and Bowen, Ed and Ram Dantu and Doria, Avri and Gopal, Ram and Salim, Jamal and Khosravi, Hormuzd and Minhazuddin, Muneyb and Wasserman, Margaret} } @article {280, title = {Signaling System 7 (SS7) Message Transfer Part 2 (MTP2) - User Adaptation Layer}, year = {2002}, url = {https://tools.ietf.org/html/rfc3331}, author = {Morneault, Ken and Ram Dantu and Sidebottom, Greg and Bidulock, Brian and Heitz, Jacob} }