Watermarking has become a technology of choice for a broad range of multimedia copyright protection applications. Watermarks have also been used to embed format-independent metadata in audio/video signals in a way that is robust to common editing. In this paper, we present several novel mechanisms for effective encoding and detection of direct-sequence spread-spectrum watermarks in audio signals. The developed techniques aim at i) improving detection convergence and robustness, ii) improving watermark imperceptiveness, iii) preventing desynchronization attacks, iv) alleviating estimation/removal attacks, and finally, v) establishing covert communication over a public audio channel. We explore the security implications of the developed mechanisms and review watermark robustness on a benchmark suite that includes a combination of audio processing primitives including: time-and frequency-scaling with wow-and-flutter, additive and multiplicative noise, resampling, requantization, noise reduction, and filtering.

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Abstract-The growing class of portable systems, such as personal computing and communication devices, has resulted in a new set of system design requirements, mainly characterized by dominant importance of power minimization and design reuse. The energy efficiency of systems-on-a-chip (SOC) could be much improved if one were to vary the supply voltage dynamically at run time. We develop the design methodology for the lowpower core-based real-time SOC based on dynamically variable voltage hardware. The key challenge is to develop effective scheduling techniques that treat voltage as a variable to be determined, in addition to the conventional task scheduling and allocation. Our synthesis technique also addresses the selection of the processor core and the determination of the instruction and data cache size and configuration so as to fully exploit dynamically variable voltage hardware, which results in significantly lower power consumption for a set of target applications than existing techniques. The highlight of the proposed approach is the nonpreemptive scheduling heuristic, which results in solutions very close to optimal ones for many test cases. The effectiveness of the approach is demonstrated on a variety of modern industrialstrength multimedia and communication applications. Index Terms-High-level synthesis, scheduling, synthesis for low power, system-on-a-chip (SOC).

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The growing class of portable systems, such as personal computing and communication devices, has resulted in a new set of system design requirements, mainly characterized by dominant importance of power minimization and design reuse. We develop the design methodology for the low power core-based real-time system-onchip based on dynamically variable voltage hardware. The key challenge is to develop effective scheduling techniques that treat voltage as a variable to be determined, in addition to the conventional task scheduling and allocation. Our synthesis technique also addresses the selection of the processor core and the determination of the instruction and data cache size and configuration so as to fully exploit dynamically variable voltage hardware, which result in significantly lower power consumption for a set of target applications than existing techniques. The highlight of the proposed approach is the non-preemptive scheduling heuristic which results in solutions very close to optimal ones for many test cases. The effectiveness of the approach is demonstrated on a variety of modern industrial-strength multimedia and communication applications.

Abstract.A certificate of authenticity (COA) is an inexpensive physical object that has a random and unique multidimensional structure S which is hard to near-exactly replicate. An inexpensive device should be able to scan object's physical "fingerprint," i.e., obtain a set of features in the form of a multidimensional signal x that pseudo-uniquely represents S. For a given "fingerprint" x and without access to S, it should be computationally difficult to construct an object of fixed dimensions with a "fingerprint" y which is at a bounded proximity from x according to a standardized distance metric. We introduce objects that behave as COAs in the electromagnetic field. The objective is to complement RFIDs so that they are physically, not only digitally, unique and hard to replicate. By enabling this feature, we introduce a tag whose information about the product can be read within a relative far-field, and also whose authenticity can be reliably verified within its near-field. In order to counterfeit a tag, the adversary faces two difficulties -a computational and a manufacturing one. The computational difficulty stems from the hardness of solving linear inverse problems in the electromagnetic field. In order to create an actual tag, the adversary must also manufacture a multidimensional object with a specific three-dimensional topology, dielectric properties, and conductivity.

We introduce a novel data center design based on emerging 60 GHz RF technology that uses wires only to deliver power to its server nodes. Fundamental limitation of wireless data centers is that the maximum number of live connections in the network is directly proportional to the full volume occupied by the data center divided by the radiating volume of a single antenna beam. Consequently, we integrate wireless transceivers and switching logic within each server node and collocate them in cylindric racks to establish a semi-regular mesh topology. Our exploration of the resulting design space shows that while attaining comparable bandwidth, our wireless data center exhibits substantially higher fault tolerance, improved latency, lower power consumption, and easier maintenance than a conventional wired data center.

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