User guide

Scrubbing the BlackBerry device heap in RAM when deleting all BlackBerry device data
To overwrite the BlackBerry® device heap that is in RAM for a BlackBerry device when content protection is turned on, the
BlackBerry device changes the state of each bit four times. The memory scrub process for a BlackBerry device performs the
following actions:
1. writes 0x33 to each byte (0011 0011
2
)
2. deletes all bytes to 0x00 (0000 0000
2
)
3. writes 0xCC to each byte (1100 1100
2
)
4. deletes all bytes to 0x00 (0000 0000
2
)
5. writes 0x55 to each byte (0101 0101
2
)
6. deletes all bytes to 0x00 (0000 0000
2
)
7. writes 0xAA to each byte (1010 1010
2
)
Scrubbing the flash memory on a BlackBerry device when deleting all BlackBerry device data
For a BlackBerry® device that is running BlackBerry® Device Software version 4.6 or later and that has content protection turned
on, the memory scrub process overwrites the NAND flash memory by writing a single character before it deletes the data. The
memory scrub process writes 0x00 to each byte (0000 0000
2
). The memory scrub process deletes all blocks and changes all
bytes to 0xFF (1111 1111
2
).
For a BlackBerry device that is running a version of BlackBerry Device Software that is earlier than version 4.6 and that has
content protection turned on, the memory scrub process overwrites the NOR flash memory by changing the state of each bit
four times. The memory scrub process performs the following actions:
1. writes 0x33 to each byte (0011 0011
2
)
2. deletes all bytes to 0xFF to each byte (1111 1111
2
)
3. writes 0xCC to each byte (0x1100 1100
2
)
4. deletes all bytes to 0xFF (1111 1111
2
)
5. writes 0x55 to each byte (0x0101 0101
2
)
6. deletes all bytes to 0xFF (1111 1111
2
)
7. writes 0xAA to each byte (0x1010 1010
2
)
8. deletes all bytes to 0xFF (1111 1111
2
)
Security Technical Overview
Scrubbing the memory of a BlackBerry device when deleting all BlackBerry device data
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