HP Designjet Printers - Secure Disk Erase

HP Secure Disk Wipe
1 Introduction
To meet the needs for higher levels of Print and Imaging security, Hewlett-Packard has implemented a security
feature in which print jobs can be securely erased from the hard disk drive. This is the secure disk erase
feature provided as a standard feature on supported Designjet printers.
The secure disk erase feature provides a choice of three different levels of disk security, which are
configurable by an administrator and may be protected from unauthorized changes with a password.
• Sanitized Erase: Conforms to the DoD 5220-22.M specification for deletion of magnetically stored data.
Using multiple data writes to eliminate trace magnetic data, Sanitized Erase prevents subsequent analysis
of the hard disk drive’s physical platters for the retrieval of data. See section 4, Specifications, for an
explanation of the erase algorithm implemented.
• Secure Erase: Provides increased performance, overwriting the existing data once, and preventing
software-based “undelete” operations to the data.
• Fast Erase: Provides the greatest performance, flagging the print job as deleted, and allowing the MFP’s
operating system to reclaim and subsequently overwrite the data when needed.
Unless otherwise specified, print job data is deleted from the disk at the completion of the print job. Multiple
mechanisms are supported for the erasure of disk drive data.
2 Data Affected
Data affected by the secure disk erase feature includes temporary files created during the printing process,
stored jobs, proof and hold jobs, disk-based fonts. Stored jobs will only be securely overwritten when they
have been deleted through the job menu on the device after the appropriate erase mode has been set. This
feature will not impact data stored on flash-based printer non-volatile RAM that is used to store default printer
settings, page counts, and so forth. This feature does not affect data stored in a system RAM disk (if utilized).
This feature will not impact data stored on the flash-based system boot RAM.
Changing the secure disk erase mode does not overwrite previous data on the disk, nor does it immediately
perform a full disk sanitization. Changing the secure disk erase mode changes how the printer cleans up
temporary data for jobs after the erase mode has been changed.
3 Default Setting
Fast Erase is the default erase mode.
4 Specifications
HP’s Sanitized Erase mode is implemented on the HP Designjet T1100ps, Z3100ps, Z6100, 4000/4500 and
they meet the U.S. Department of Defense 5220-22.M requirements for clearing disk media. Using a
succession of multiple data overwrites, including the validation of the success of those overwrites, Sanitized
Erase can prevent the subsequent physical analysis of the hard disk drive’s media for recovery of data:
1. Each byte of file data is overwritten with the fixed character pattern (binary 01001000).
2. Each byte of file data is overwritten with the compliment of the fixed character pattern (binary
10110111).
3. Each byte of file data is overwritten with a random character:
a. A 32k byte buffer of random characters is generated for each file delete operation using the
device’s unique uptime as the seed.
HP Designjet Printers 3