Secret code protecting cellphone calls is broken

[esh]

When I was writing an optimisation algorithm for analysis of electric charges many years back I rapidly discovered that one should never trust the random number generator -- especially if it happened to be the default Microsoft one. After many hundred days of CPU time exhausted I discovered much to my dismay the results were skewed depending on whether the machines ran Windows 2000 or Windows XP. Both random number generators had sufficient mutation rate but after mere tens of thousands of cycles the 'random' sequence was quite clearly repeating, with a different break depending on the operating system. The answer? I used an open source assembly written 3rd-party random number generator, and never saw the problem again.

The important thing to understand with most random number generators is that they depend upon a value known as the 'seed'. If you start the random number generator with the same seed twice, you get the same sequence of numbers.

[somanyholes]

cipher used in encrypting 3G GSM communications. KASUMI is also known as A5/3, which is confusing because it's only been a week since breaks on A5/1, a completely different cipher, were publicized. So if you're wondering if this is last week's news, it isn't. It's next week's news.

http://www.emergentchaos.com/archives/2010/01/another_week_another_gsm.html