Appendix D: Blackberry Device Wipe Process; Memory Scrub Process For Ram On Blackberry Devices - Blackberry ENTERPRISE SOLUTION SECURITY - ENTERPRISE SOLUTION - SECURITY TECHNICAL Overview

BlackBerry Enterprise Solution

Appendix D: BlackBerry device wipe process

A BlackBerry device wipe process is designed to delete and overwrite the BlackBerry device memory.
1. The BlackBerry device sets a Device Under Attack flag in the NV store.
If a user removes the battery or the battery power drops to zero before the BlackBerry device data wipe
ends, when the BlackBerry device power is restored (in other words, a user replaces the battery), the
BlackBerry device wipe process continues because the Device Under Attack flag is still present.
2. If content protection of master encryption keys is turned on, the BlackBerry device overwrites the copy of
the grand master key in RAM with zeroes.
3. The BlackBerry device deletes its binding with the BlackBerry Enterprise Server by deleting the IT policy
public key from the NV store. This allows the BlackBerry device to bind to a new BlackBerry Domain.
The IT policy public key does not undergo memory scrubbing because it is not a protected or hidden value.
4. If applicable, the BlackBerry device deletes the smart card binding information from the NV store. This
allows the BlackBerry device to bind to a new smart card. See "Unbinding the smart card from the
BlackBerry device" on page 65 for a list of the information deleted during the unbinding process.
5. The BlackBerry device wireless transceiver turns off.
6. The BlackBerry device deletes data in the persistent store in flash memory, including references to the
master encryption key.
7. The BlackBerry device overwrites flash memory with zeroes.
8. The BlackBerry device memory scrub process overwrites the BlackBerry device heap in RAM, changing the
state of each bit four times. For more information, see "Memory scrub process for RAM on BlackBerry
devices" below.
9. The BlackBerry device clears the BlackBerry device password from the NV store.
10. The BlackBerry device formats the external memory file system if it exists on the BlackBerry device.
11. If content protection is turned on, the BlackBerry device memory scrub process overwrites the BlackBerry
device flash memory file system. For more information, see "Memory scrub process for flash memory on
BlackBerry devices" below.
12. If content protection is turned on, the BlackBerry device memory scrub process overwrites the external
memory file system if it exists on the BlackBerry device. For more information, see "Memory scrub process
for flash memory that stores user-saved files on BlackBerry devices" below.
13. The BlackBerry device clears the Device Under Attack flag from the NV store.
14. The BlackBerry device restarts.

Memory scrub process for RAM on BlackBerry devices

To overwrite the BlackBerry device heap in RAM by changing the state of each bit four times, the BlackBerry
device memory scrub process performs the following actions:
1. Writes 0x33 to each byte (0011 0011
2. Clears all bytes to 0x00 (0000 0000
3. Writes 0xCC to each byte (1100 1100
4. Clears all bytes to 0x00 (0000 0000
5. Writes 0x55 to each byte (0101 0101
6. Clears all bytes to 0x00 (0000 0000
7. Writes 0xAA to each byte (1010 1010
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2009 Research In Motion Limited. All rights reserved.
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