The “Schredder affair” has hit big waves in Austria. What is really behind it and how should companies deal with the problem of data deletion?
When computers or network printers are sold or disposed of, the data on the hard drives must be securely erased. Sensitive data may not be made accessible to unauthorized persons.
But why is data stored on a printer? Why is not it enough to format the harddrive? A formatted hard drive is empty, right?
Why do printers store data?
Not every printer stores data. Copiers that scan multiple pages before the pages are fully printed, must save the data until printed. After that, the data will be deleted. Because of this, almost all major office printers have built-in hard drives. In addition to data about the actual printed or copied documents, these printers also store data such as an e-mail directory to deliver scans, a phone book to deliver faxes, and information about access permissions.
What happens during “normal” deletion?
In any case, if such a printer is disposed of or resold, a factory reset will be made to delete all settings and directories (email, phone, …).
On the printer hard disk itself, there are no data that are deliberately kept there. The data there is usually deleted by the printer immediately after the print job has been completed. When deleting data, it is noted that the location on the hard disk is available again, but the data is not immediately overwritten. Therefore, it is as if a sheet written on with a pencil comes back into the supply stack. Only when really written on it, the old data are “erased”.
How will I delete it safely?
This deleted data can be restored by an expert. For this reason, if a computer or printer is disposed of, the hard disk should be SAFELY DELETED or DESTROYED.
Data is safely deleted when the previous data is overwritten with new data. Unfortunately that is not as easy as it sounds.
Overwriting all data on a hard disk is relatively easy with appropriate software. If the data is overwritten, it can not be recovered. Unfortunately, the current hard drive technology beats us. To increase the life of the hard disk or to avoid errors, some hard drives decide on their own that some areas are no longer used. These are therefore not overwritten. So even a hard drive that looks completely empty can still contain (few) data that an expert can read out.
The difference between a correctly deleted hard disc and a hard disk from which an expert can recover almost all data is not noticeable to a layman.
For this reason, the destruction of the hard drive by a suitable service provider for a layman is the easiest way.
What is behind the shredder affair now?
As described, printer disks do not contain data archived there after the print job. All data on the hard disks are already deleted. Only an expert in data recovery can recover some of the data – those that have not yet been deleted.