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Showing posts from December, 2010

True Random Numbers from

Much of security relies on randomness - encryption keys should be random and random passwords are more secure than dictionary words or predictable sequences. The problem is, how do we generate a random number?
Well, actually, this is a trick question. The answer is that you can't generate random numbers, but you can observe them. Most programming languages give you a random number generator, so why not just use that? Well, it's not actually a random number generator, but a Pseudo-Random Number Generator (PRNG), or more accurately a Pseudo-Random Sequence Generator (PRSG). Given the same seed value, it will produce the same output every time. Try seeding the random number function in your favourite programming language then run your program a few times. You should see the same numbers coming out each time.
The reason for this is the function used to produce random numbers is just a mathematical formula that takes an input and gives an output. To have a random number out, you n…

HDD Tools & Other Malware Removal

Recently I had someone come to me with their laptop saying that they had a new anti-virus program that they didn't remember installing and that 'other things' on their laptop didn't seem to work any more. The same thing happened to a corporate desktop machine I was asked about a couple of weeks later, that was originally running McAfee. Finally, two days ago I saw another corporate machine running McAfee that was saying that it had a hard drive failure. A tool, called HDD Tools, then automatically ran to diagnose the problem and stated that if they purchased the full HDD Tools product then it could fix the problem.

Each of these was a piece of malware that had infected the machine and was trying to get the user to enter their credit card details into a website so that money can be taken from their account and maybe their card cloned. These malware programs go along with the fake anti-virus software that the APWG have reported a huge rise in recently. These are a collec…