Its all in the memory, literally!

We all think that when you turn your computer off; well it’s really off and all the data stored on the disc is safe and anything in the memory chips (RAM) has gone.

However, according to a group of Princeton University researchers nothing could be further from the truth!

“The root of the problem lies in an unexpected property of today’s DRAM memories. DRAMs are the main memory chips used to store data while the system is running. Virtually everybody, including experts, will tell you that DRAM contents are lost when you turn off the power. But this isn’t so. Our research shows that data in DRAM actually fades out gradually over a period of seconds to minutes, enabling an attacker to read the full contents of memory by cutting power and then rebooting into a malicious operating system.”

“Interestingly, if you cool the DRAM chips, for example by spraying inverted cans of “canned air” dusting spray on them, the chips will retain their contents for much longer. At these temperatures (around -50 °C) you can remove the chips from the computer and let them sit on the table for ten minutes or more, without appreciable loss of data. Cool the chips in liquid nitrogen (-196 °C) and they hold their state for hours at least, without any power. Just put the chips back into a machine and you can read out their contents.”

Why is this suddenly being talked about? I seems that many disk encryption/security products keep vital identity keys in RAM and it now appears that under certain circumstances, it may be possible for hackers to circumvent the security of disk encryption tool.

You can find more details here, as well a PDF if you want to read the full research details.

Amazing how preconceived ideas are suddenly found to be full of holes!