How secure is secure erase on a Time Capsule?

mpw_amherst

I've just replaced an old Time Capsule with a newer one. However, I wondered how secure the secure erase function is if I wanted to try and sell the old one on ebay? I'm anxious about selling it if there might be anyway  for a buyer to access my old backups.

marvin

mpw_amherst said:

I've just replaced an old Time Capsule with a newer one. However, I wondered how secure the secure erase function is if I wanted to try and sell the old one on ebay? I'm anxious about selling it if there might be anyway  for a buyer to access my old backups.

As long as you don't just do a quick erase, the erase will be secure. The zero-out option is the minimum for secure erase but also all you'd need. This overwrites every single bit of data on the drive. If you think of your drive like rows of switches (billions of them) in on/off positions, this zero-out option sets them all to zero. Quick erase leaves all the switches in place (and recoverable), it just marks them in a way that they can be freely overwritten in future. Some advanced low-level software can measure the magnetic states after the switches have been set to zero in a zero-out erase pass to figure out what they were but only people in forensics would do this. This is what the multiple write options are for e.g erasing classified info.

You can actually manually do the equivalent of zeroing a drive out by copying a large file onto it after a quick erase. The quick erase wipes the drive index and the file write resets all the data on the drive. You just have to make sure to fill it up. People should always zero-out a drive or quick erase then fill it with dummy data before selling it on.

mpw_amherst

That's very helpful, Marvin. Thanks so much!