When Computer Security Crashes into Multimedia

A casual glance on the web, or in your local newspaper, will quickly convince a reader that the two of the hottest fields in computer science right now are computer security and multimedia. Unfortunately, these fields often seem at odds with each other. This talk will take two case studies and show how the fields cause problems for each other. First, I discuss how multimedia can cause problems for computer security. I show how we are able to take recordings of a user typing at a keyboard and using only a generic $10 microphone and an assumption that the user is typing English, we can from the recording alone determine the text being typed with 96% accuracy. In fact, after training this system on English text, we can accurately recover passwords typed by the user. (This is joint work with L. Zhuang and F. Zhou [1].) Second, I discuss how security can cause problems for multimedia. Taking the example of filtering for copyright protected content, I discuss a variety of proposed schemes for restricting distribution of audio files. I conclude with an overview of other research areas where the fields computer security and multimedia jointly have significant contributions to make.