Exposing digital forgeries

Those wizards at Dartmouth's Computer Science Department have come up with a clever technique for automatically detecting forged JPEG images. To quote from the abstract: We describe an efficient technique that automatically detects duplicated regions in a digital image. This technique works by first applying a principal component analysis to small fixed-size image blocks to yield a reduced dimension representation. This representation is robust to minor variations in the image due to additive noise or lossy compression. Duplicated regions are then detected by lexicographically sorting all of the image blocks. We show the efficacy of this technique on credible forgeries, and quantify its robustness and sensitivity to additive noise and lossy JPEG compression.

Webcam Virus

Bob Sullivan at MSNBC writes of a new computer virus that turns on webcams and sends out the contents to willing hackers. Sounds like something the FBI would have dreamed up.

800-page Textbook for $0

More and more high-quality information is showing up for free on the Internet. Case in point: you can now go online and access an 800-page textbook on how to administer a Cisco-powered computer network. The book, by information technology and IT security professor Matt Basham of St. Petersburg College in Clearwater, FL, is designed for people with very minimal computer experience who suddenly find themselves responsible for administering a TCP/IP-based network. Two thousand copies were downloaded within the first few days that it was online. Interested? Here’s where to get it.