http://technology.newscientist.com/article/dn14124-compressed-web-phone-calls-are-easy-to-bug.html By David Robson NewScientist.com news service 12 June 2008 Plans to compress internet (VoIP) phone calls so they use less bandwidth could make them vulnerable to eavesdropping. Most networks are currently safe, but many service providers are due to implement the flawed compression technology. The new compression technique, called variable bitrate compression produces different size packets of data for different sounds. That happens because the sampling rate is kept high for long complex sounds like "ow", but cut down for simple consonants like "c". This variable method saves on bandwidth, while maintaining sound quality. VoIP streams are encrypted to prevent eavesdropping. However, a team from John Hopkins University in Baltimore, Maryland, US, has shown that simply measuring the size of packets without decoding them can identify whole words and phrases with a high rate of accuracy. [...] _______________________________________________ Attend Black Hat USA, August 2-7 in Las Vegas, the world's premier technical event for ICT security experts. Featuring 40 hands-on training courses and 80 Briefings presentations with lots of new content and new tools. Network with 4,000 delegates from 50 nations. Visit product displays by 30 top sponsors in a relaxed setting. http://www.blackhat.com
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