05/2011

vol. 54 no. 05

Practice

44 The One-Second War Finding a lasting solution to the leap seconds problem has become increasingly urgent. By Poul-Henning Kamp

49 Mobile Application Development: Web vs. Native

Web apps are cheaper to develop and deploy than native apps, but can they match the native user experience? By Andre Charland and Brian LeRoux

54 Weapons of Mass Assignment A Ruby on Rails app highlights some serious, yet easily avoided, security vulnerabilities.

By Patrick McKenzie

Articles’ development led by queue.acm.org

Contributed Articles

60 Brain-Computer Interfaces for Communication and Control

The brain’s electrical signals enable people without muscle control to physically interact with the world. By Dennis J. McFarland and Jonathan R. Wolpaw

67 The Future of Microprocessors Energy efficiency is the new fundamental limiter of processor performance, way beyond numbers of processors.

By Shekhar Borkar and Andrew A. Chien

78 Privacy-Preserving Network Forensics Privacy-preserving attribution of IP packets can help balance forensics with an individual’s right to privacy. By Mikhail Afanasyev, Tadayoshi Kohno, Justin Ma, Nick Murphy, Stefan Savage, Alex C. Snoeren, and Geoffrey M. Voelker

Challenges and Business Models for Mobile Location-based Services and Advertising Mobile advertising will become more pervasive and profitable, but not before addressing key technical and business challenges. By Subhankar Dhar and Upkar Varshney

Is Open Source Security a Myth? What does vulnerability and patch data say? By Guido Schryen

Review Articles

88 Proving Program Termination

In contrast to popular belief, proving termination is not always impossible. By Byron Cook, Andreas Podelski, and Andrey Rybalchenko

Research Highlights

100 Technical Perspective Complex Financial Products: Caveat Emptor

By David C. Parkes

101 Computational Complexity and Information Asymmetry in Financial Products

By Sanjeev Arora, Boaz Barak, Markus Brunnermeier, and Rong Ge

108 Technical Perspective Images Everywhere Looking for Models By Guillermo Sapiro

109 Self-Similarity-based Image Denoising

By Antoni Buades, Bartomeu Coll, and Jean-Michel Morel

IlluS Tra TIon By Gary ne Ill

Invisible Work in Standard Bibliometric Evaluation of Computer Science Most of a computer scientist’s production can go uncounted if a standard bibliographic service is used. By Jacques Wainer, Siome Goldenstein, and Cleo Billa

Association for Computing Machinery Advancing Computing as a Science & Profession