Computer Science Canada Secure Deletion in a Single Overwrite? |
| Author: | Dan [ Wed Mar 11, 2009 12:28 pm ] |
| Post subject: | Secure Deletion in a Single Overwrite? |
This artical has been going around the web but i found it intersting enought to post about just the same: http://www.h-online.com/news/Secure-deletion-a-single-overwrite-will-do-it--/112432 A quick summary is that it has been a long held belife in the computer seucrity world that to securely delete somthing from a harddrive you have to repeativel write over it with random data up to at least 7 times. In fact every software program i have ever used to do this has allways offered options to do it an reiduless amount of times and warned that the only secure way was at least X times (where X is noraml more then 5 or 7 depedning on who you talk two). However it truns out that a rencet study done by forensics expert witch was persented at ICISS 2008 shows that the probality of recovering any signficat amount of data after just one overwrite with 0s is almost 0%. Recovery of a singal bit has just over a 50% chance if you it's excact location but the odds of that are less then 1% (and thats just to recover a 0 or a 1). So should we all change our wiping programs from the guttman 35 pass wipes of randomness or our DoD 7 pass wipe with a singal one of 0s? I know for my personal computers this knowagle is going to save alot of cpu time and make my hard drives alot more happy with me. |
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| Author: | Euphoracle [ Wed Mar 11, 2009 2:32 pm ] |
| Post subject: | RE:Secure Deletion in a Single Overwrite? |
I modified a GPL "wiper" to do a pseudorandom pass and then a zero pass already. I didn't find it useful to wipe everything tens of times. The former is simply because I thought it would be more secure, the latter because I figured it's magnetic, how much can they possibly recover, since odds are, it'll be written over again soon, or broken due to defragmentation (windows). Who would of thought I was right  |
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