-The Interdisciplinary TelecommunicationsProgram at the University of Colorado has developed an internet based remote laboratory environment for master's level graduate students; our suite of telecommunications experiments substantially extends prior work focused on networking equipment, by (1) providing a systems focus, (2) enabling multiple reinforcing methods of accessing the educational material, (3) providing a configuration matrix to support realtime network reconfigurations (of real network elements) (4) undertaking a careful assessment of the learning environment. The goal was to create an environment that reproduced (not just emulated) the lab experience.We recently completed the final phase of this project focusing on assessment of this learning tool; such assessment is still rare in the literature on remote laboratories.We describe the project from three perspectives; students' exam results, students' lab reports, and students' satisfaction with the distance experience (based on interviews). We conclude that our remote laboratories provide similar learning outcomes to their in class analogues, but that there are important differences in student perceptions of the experience, including perceived difficulty and pace.

Selective encryption exploits the relationship between encryption and compression to reduce encryption requirements, saving in complexity and facilitating new system functionality. Selective encryption of MPEG video streams has been proposed in a number of variations, yet has seen little application to date. Here we focus on high encryption savings, targeting 10% of the bit stream or less encrypted, moderate security in the sense that the content is degraded to the point that purchase would be preferred over consuming free content, no impact on compression efficiency, and a cryptanalytic approach to validating security. We find that adequate security is plausible if the compressor is cooperative or at least neutral with respect to the selective encryption system, but implausible if the compressor is operated antagonistically. The unusually low encryption targeted makes application of this solution appealing.

-Selective encryption is a technique to save computational complexity or enable interesting new system functionality by only encrypting a portion of a compressed bitstream while still achieving adequate security. Although suggested in a number of specific cases, selective encryption could be much more widely used in consumer electronic applications ranging from mobile multimedia terminals through digital cameras were it subjected to a more thorough security analysis. We describe selective encryption and develop a simple scalar quantizer example to demonstrate the power of the concept, list a number of potential consumer electronics applications, and then describe an appropriate method for developing and analyzing selective encryption for particular compression algorithms. We summarize results from application of this method to the MPEG-2 video compression algorithm.

Voice over IP (VoIP) promises to up-end a century-old model of voice telephony by breaking the traditional monolithic service model of the public switched telephone network (PSTN) and changing the point of control and provision from the central office switch to the end user's device. Placing intelligence at the edge, in the Internet tradition, has a number of consequences: a wider community of developers-in particular the large community of Web service developers-can work on voice applications; open interfaces and decomposable functionality facilitate multi-vendor and "homegrown" solutions; and open source and nonproprietary software development can facilitate innovation and experimentation. Users themselves will take a much bigger role in defining, implementing, and controlling the features of telephone services. Contrast this with the more-than-100-year institution of traditional voice service through a single ubiquitous dedicated network, the PSTN. Characteristically, in the PSTN, services are developed hand-in-hand with vendors of the hardware (the circuit switch), the product and its operation are a closely guarded proprietary concern, and, consequently, relatively few vendors of DDO S t a k e s o n a w h o l e n e w m e a n i n g .

Selective encryption is a technique to save computational complexity or enable interesting new system functionality by only encrypting a portion of a compressed bitstream while still achieving adequate security. Although suggested in a number of specific cases, selective encryption could be much more widely used in consumer electronic applications ranging from mobile multimedia terminals through digital cameras were it subjected to a more thorough security analysis. We describe selective encryption and develop a simple scalar quantizer example to demonstrate the power of the concept, list a number of potential consumer electronics applications, and then describe an appropriate method for developing and analyzing selective encryption for particular compression algorithms. We summarize results from application of this method to the MPEG-2 video compression algorithm.