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How secure is the bulit-in Cipher utility that can wipe out unrecoverable data on old harddisk?

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I can't find the official documentation from Microsoft stating it, but I remember seeing that it uses a three-pass method for wiping the data. On the first round it overwrites with 0's, then on the second with 1's, then the third pass with random bits. So, it's not bad.

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So it will really not be recoverable? Because we are dealing with formatting data in government office. – James Feb 24 '11 at 13:37
@James Well, it's a similar technique to a lot of other tools that provide the same functionality. Whether or not it's good enough for your environment is a judgment call that needs to be done by your organization, I can't make that call for you. I won't absolutely guarantee it but I don't know of any tools that will be able to recover that. – squillman Feb 24 '11 at 13:52
@James - If you are in a government office you should have guidelines on how to erase data safely. That said, a three pass wipe is secure enough that it would take a pretty high-tek lab to recover any data. That would limit it to data rescue professionals or law enforcement. And if you are scared of that put the drive in a shredder. – Nifle Feb 24 '11 at 13:54
As far as I know data recovery on bits that have already been flipped more than a couple times since deletion is basically in the realm of theory and takes a lot of fancy equipment an work. That said, if you're a government office you'd have to check to see whether a 3 pass delete meets your guidelines. You could always just do another pass or two with cipher to get it up to 6 or 9. That or get a tool specifically designed to do DoD level wipes. – Tofystedeth Feb 24 '11 at 15:00

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