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ERASING A MEMORY KEY
By JB Burke


Q. I want to securely erase my memory key, so no one can recover the confidential information I had written on it. How do I do that?

A. When you write data to a conventional disk drive, it is stored magnetically in a particular place on that drive. Thus, to completely remove it, you should overwrite it several times with random ones and zeros. This can be accomplished by free programs such as eraser.exe They let you choose how many times to overwrite the data – the more important the data, the more times you’d overwrite it.

Memory sticks (also called memory keys or thumb drives), solid state drives and SD cards are all built from memory chips, much like the RAM memory in your computer. Since your memory key isn’t magnetic storage, different rules apply. The memory key technology only allows a limited number of writes to a memory key before it begins to fail. They use a technology called “wear leveling”, which assures all areas of the memory key are used equally. If you use a program like eraser.exe, trying to overwrite a single file will fail. The data written by eraser will go to random areas on the memory key (“wear leveling”).

What you must do is overwrite (erase) the entire memory key ONE TIME only. Overwriting multiple times will just shorten the life of the memory stick. Remember to backup to disk any
memory key files you don’t want to lose before you erase the memory key.

Published: Courier 10/2/11 - Page 5C