Amit Pande

Securing Multimedia Content Using Joint Compression and Encryption

Algorithmic parameterization and hardware architectures can ensure secure transmission of multimedia data in resource-constrained environments such as wireless video surveillance networks, telemedicine frameworks for distant health care support in rural areas, and Internet video streaming. Joint multimedia compression and encryption techniques can significantly reduce the computational requirements of video processing systems. The authors present an approach to reduce the computational cost of multimedia encryption while also preserving the properties of compressed video. A hardware-amenable design of the proposed algorithms makes them suitable for real-time embedded multimedia systems. This approach alleviates the need for additional hardware for encryption in resource-constrained scenarios and can be otherwise used to augment existing encryption methods used for content delivery on the Internet or in other applications. This work shows how two compression blocks for video coding--a modified frequency transform (called a secure wavelet transform or SWT) and a modified entropy coding scheme (called a chaotic arithmetic coding or CAC)--can be used for video encryption. Experimental results are shown for selective encryption using the proposed schemes.

Mobile video chat: issues and challenges

The next generation of cellular communication needs to endure a higher demand for enhanced real-time multimedia support to end users. Among interactive video applications, use of mobile video chat is on the rise in both the enterprise and consumer worlds. Mobile video chats are resource-constrained and heterogenous with varying display sizes, processing powers, network conditions, and battery levels, and pose real-time delivery constraints unlike traditional video streaming applications. With the demand for anywhere any time connectivity for video chat, it becomes quintessential to develop techniques that adapt to the underlying network, optimize the device architectures, and provide the best possible video chat experience to end users. In this article, we identify main limitations and challenges in mobile video chat. We further discuss possible solutions and propose research directions to make video chat a good experience.

Edge-prioritized channel- and traffic-aware uplink Carrier Aggregation in LTE-advanced systems

LTE-Advanced (LTE-A) systems support wider transmission bandwidths and hence, higher data rates for bulk traffic, as a result of Carrier Aggregation (CA). However, existing literature lacks efforts on channel-aware CA, especially in the uplink. The cell-edge users particularly suffer from exhaustion of resources, higher fading losses, lower SINR values (hence, requiring a higher power consumption) due to lossy channels that their traffic requirements are least-satisfied by channel-blind CA. This paper addresses the above concern by proposing an edge-prioritized channel- and traffic-aware uplink CA comprising Component Carrier (CC) assignment and resource scheduling. The LTE-A UEs are spatially-grouped and the under-represented edge UE groups, having the least assignable resources (good CCs), are prioritized for CA. This results in assigning the best channels to the edge groups. The frequency resources are scheduled to the groups based on inter-group and intra-group Proportional Fair Packet Scheduling (PFPS) in the time and frequency domains respectively, to resolve resource contention. The proposed approach outperforms the existing channel-blind Round-Robin and channel-aware Opportunistic CA, in terms of overall uplink throughput, by 33% in CC assignment and 21% in PFPS, in addition to significant throughput improvements for the edge UEs.

Sensor-assisted facial recognition: an enhanced biometric authentication system for smartphones

Facial recognition is a popular biometric authentica-tion technique, but it is rarely used in practice for de-vice unlock or website / app login in smartphones, alt-hough most of them are equipped with a front-facing camera. Security issues (e.g. 2D media attack and vir-tual camera attack) and ease of use are two important factors that impede the prevalence of facial authentica-tion in mobile devices. In this paper, we propose a new sensor-assisted facial authentication method to over-come these limitations. Our system uses motion and light sensors to defend against 2D media attacks and virtual camera attacks without the penalty of authenti-cation speed. We conduct experiments to validate our method. Results show 95-97% detection rate and 2-3% false alarm rate over 450 trials in real-settings, indicat-ing high security obtained by the scheme ten times faster than existing 3D facial authentications (3 sec-onds compared to 30 seconds).

Tracking Health Data Is Not Enough: A Qualitative Exploration of the Role of Healthcare Partnerships and mHealth Technology to Promote Physical Activity and to Sustain Behavior Change.

Background Despite the recent explosion of the mobile health (mHealth) industry and consumer acquisition of mHealth tools such as wearable sensors and applications (apps), limited information is known about how this technology can sustain health behavior change and be integrated into health care. Objective The objective of the study was to understand potential users’ views of mHealth technology, the role this technology may have in promoting individual activity goals aimed at improving health, and the value of integrating mHealth technology with traditional health care. Methods Four focus groups were conducted with adults interested in sharing their views on how mHealth technology could support wellness programs and improve health. Participants (n=30) were enrolled from an employee population at an academic health institution. Qualitative thematic analysis was used to code transcripts and identify overarching themes. Results Our findings suggest that tracking health data alone may result in heightened awareness of daily activity, yet may not be sufficient to sustain use of mHealth technology and apps, which often have low reuse rates. Participants suggested that context, meaning, and health care partnerships need to be incorporated to engage and retain users. In addition to these findings, drivers for mHealth technology previously identified in the literature, including integration and control of health data were confirmed in this study. Conclusions This study explores ways that mHealth technologies may be used to not only track data, but to encourage sustained engagement to achieve individual health goals. Implications of these findings include recommendations for mHealth technology design and health care partnership models to sustain motivation and engagement, allowing individuals to achieve meaningful behavior change.

Video Delivery Challenges and Opportunities in 4G Networks

Wireless network traffic is dominated by video and requires new ways to maximize the user experience and optimize networks to prevent saturation. The exploding number of subscribers in cellular networks has exponentially increased the volume and variety of multimedia content flowing across the network. This article details some challenges in delivery of multimedia content over 4G networks for several application scenarios. To augment the increasing demand for video applications in cellular and wireless traffic, these challenges must be efficiently addressed.

BayWave: BAYesian WAVElet-based image estimation

Image denoising is an important step in image compression and other image processing algorithms. Hard and soft thresholding algorithms are often used to denoise the images. Recently wavelet transform has been used as a tool to denoise the images. However, there are problems associated with the thresholding algorithms. There is no subjective way to determine the threshold. In this work, we implement a simple Bayesian theory to obtain optimal threshold for such algorithms. MATLAB simulations were performed to validate the working of Bayesian thresholding method.

Design and analysis of efficient reconfigurable wavelet filters

Real-time image and multimedia processing applications such as video surveillance and telemedicine can have dynamic requirements of system latency, throughput, and power consumption. In this paper we discuss the design of reconfigurable wavelet filters for image processing applications that can meet such dynamic requirements. We generate several efficient hardware designs based on a derived family of bi-orthogonal 9/7 filters. An efficient folded and multiplier-free implementation of a 9/7 filter is obtained with the help of nine adders, which is a significant improvement over other existing approaches. We also propose an architecture that allows for on-the-fly switching between 9/7 and 5/3 filter structures. A performance comparison of these filters and their hardware requirements with other existing approaches demonstrates the suitability of our choice.

Design and hardware implementation of a chaotic encryption scheme for real-time embedded systems

Chaotic encryption schemes are believed to provide a greater level of security than conventional ciphers. In this paper, a chaotic stream cipher is first constructed and then its hardware implementation details using FPGA technology are provided. Logistic map is the simplest chaotic system and has a high potential to be used to design a stream cipher for real-time embedded systems. The cipher uses a pseudo-random sequence generator based on modified logistic map (MLM) and a random feedback scheme. MLM has better chaotic properties than the logistic map in terms of uniformity of bifurcation diagram and also avoids the stable orbits of logistic map, giving a more chaotic behavior to the system. The proposed cipher gives 16 bits of encrypted data per clock cycle. The hardware implementation results over Xilinx Virtex-6 FPGA give a synthesis clock frequency of 93 MHz and a throughput of 1.5 Gbps while using 16 hardware multipliers. This makes the cipher suitable for embedded devices which have tight constraints on power consumption, hardware resources and real-time parameters.

MagPairing: Pairing Smartphones in Close Proximity Using Magnetometers

With the prevalence of mobile computing, lots of wireless devices need to establish secure communication on the fly without pre-shared secrets. Device pairing is critical for bootstrapping secure communication between two previously unassociated devices over the wireless channel. Using auxiliary out-of-band channels involving visual, acoustic, tactile, or vibrational sensors has been proposed as a feasible option to facilitate device pairing. However, these methods usually require users to perform additional tasks, such as copying, comparing, and shaking. It is preferable to have a natural and intuitive pairing method with minimal user tasks. In this paper, we introduce a new method, called MagPairing, for pairing smartphones in close proximity by exploiting correlated magnetometer readings. In MagPairing, users only need to naturally tap the smartphones together for a few seconds without performing any additional operations in authentication and key establishment. Our method exploits the fact that smartphones are equipped with tiny magnets. Highly correlated magnetic field patterns are produced when two smartphones are close to each other. We design MagPairing protocol and implement it on Android smartphones. We conduct extensive simulations and real-world experiments to evaluate MagPairing. Experiments verify that the captured sensor data on which MagPairing is based has high entropy and sufficient length, and is nondisclosure to attackers more than few centimeters away. Usability tests on various kinds of smartphones by totally untrained users show that the whole pairing process needs only 4.5 s on average with more than 90% success rate.