[HN Gopher] Research of RAM data remanence times
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Research of RAM data remanence times
Author : mkopec
Score : 34 points
Date : 2024-12-13 23:16 UTC (3 days ago)
(HTM) web link (blog.3mdeb.com)
(TXT) w3m dump (blog.3mdeb.com)
| westurner wrote:
| From https://blog.3mdeb.com/2024/2024-12-13-ram-data-decay-
| resear... :
|
| > _The main goal is to determine the time required after powering
| off the platform for all the data to be irrecoverably lost from
| RAM._
|
| Cold boot attack: https://en.wikipedia.org/wiki/Cold_boot_attack
|
| Data remnance: https://en.wikipedia.org/wiki/Data_remanence
|
| Ironically, quantum computers have the opposite problem;
| coherence times for QC qubits are still less than a second: there
| is not yet a way to store qubits for even one second.
|
| (2024: 291+-6us, 2022: 20us)
|
| "Cryogenically frozen RAM bypasses all disk encryption methods"
| (2008) https://www.zdnet.com/article/cryogenically-frozen-ram-
| bypas...
|
| And that's part of why secure enclaves and TPM.
| westurner wrote:
| From https://news.ycombinator.com/item?id=37099515 :
|
| > _If quantum information is never destroyed - and classical
| information is quantum information without the complex term i -
| perhaps our [RAM] states are already preserved in the universe;
| like reflections in water droplets in the quantum foam_
|
| According to the "Air gap malware" Wikipedia article's
| description of GSMem, the x86 RAM bus can be used as a low
| power 3G antenna. And, HDMI is an antenna, and, Ungrounded
| computers leak emanations to the ungrounded microphone port on
| the soundcard.
|
| Air gap malware: https://en.wikipedia.org/wiki/Air-gap_malware
|
| Stochastic forensics:
| https://en.wikipedia.org/wiki/Stochastic_forensics
| myself248 wrote:
| Back in the day, we called that
| https://en.wikipedia.org/wiki/Van_Eck_phreaking
| drpixie wrote:
| What's with giving error rates as a count of bits, when it's not
| clear how much DRAM was tested? There's a comment that the error
| was around 50% but the graphs should be error percentage, not
| some (meaningless) absolute number!
|
| And there was an interesting feature - error rates didn't seem to
| change linearly with time, but (strongly for DDR4 and less so for
| DDR5) the error rate changes in intervals of 8 seconds. That's
| very much unexpected, so needs a good explanation or indicates a
| likely error in their procedure.
| Almondsetat wrote:
| I agree that absolute numbers are a bit strange, but the
| article states exactly which model of memory was used, namely a
| W-NM56S508G SODIMM for DDR5 and a KF432C16BB/4 DIMM for DDR4,
| not to mention the most important part is measuring their
| different performance between generations
| JoachimSchipper wrote:
| The error rate is given per bit, not per second, i.e. every few
| bars represents a distinct DRAM chip. That makes some sense,
| and the article explains quite well why DRAM would behave like
| that... but I agree that I had to read the article at least
| twice to figure out that the x-axis on the graph represents the
| lower bit of the address line!
|
| Still, it's nice to have at least some modern data;
| https://www.usenix.org/legacy/event/sec08/tech/full_papers/h...
| is awesome and has much more extensive measurements, but
| machines from 2007 are somewhat less relevant today.
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