Is there any research into the recovery of data stored in an EEPROM after the high-voltage bulk erase (not bytewise or pagewise erase) operation? I'm wondering about typical low-capacity EEPROMs which use Fowler–Nordheim tunneling and which have a dedicated erase pin that's brought to a high voltage to erase everything at once. I specify this to distinguish what I mean from "false" EEPROM like NOR flash.

I ask because I am trying to understand the security ramifications of using this for persistent storage of an encryption key, for example in a storage device with SED (Self-Encrypting Drive) capability.

  • 1
    As a side note: I would think twice about relying on SED for encryption. In EO 2018 a research paper was released titled Self-encrypting deception: weaknesses in the encryption of solid state drives which illustrated the weaknesses in the implementations of these drives. Microsoft also stopped relying on them when applying BitLocker and will no longer rely on hardware encryption when an SED is detected. – Igor Oct 30 '19 at 14:15
  • @Igor I understand. SED was just an example. This is for something I'm making myself. – forest Oct 31 '19 at 0:04

You are looking for details on the phenomenon of data remanence. There is not much data freely available.

The semi manufacturers have little incentive to perform in-depth testing, There are no financial benefits, and their findings may contradict their claims regarding secure erasure.

Likewise, system integrators have no incentive to share their findings with potential competitors.

I assume intelligence agencies have programs for this, but they will never disclose significant details---at least not while they are relevant.

This leaves academic sources as your best bet. Unfortunately, academic articles are often hidden behind paywalls and/or only discoverable via subscription services. Universities pay for access as a basic cost of running their business, but it is not particularly affordable for individuals.

In the rare event an article such as this one is published as "open access", then it is available without a subscription to the publishing journal or the academic database(s) which include that journal.

From the link to the publisher's details, you can see that only 5 articles from the Journal of Hardware and Systems Security are open access. That is not even one full issue.

If you have an affiliation with a university or a company that is willing to provide access, there are hardware/systems security publications that likely contain the information you seek---without that, you likely need to experiment personally.

  • Intelligence agencies often serve two roles. Gathering intelligence, but also protecting intelligence from their own nation from use by bad actors. You could look at the recommendations of intelligence agencies about whether to trust SED's for data destruction, and this might reveal something. – Steve Sether Oct 30 '19 at 15:45
  • OP is looking for specifics, not general recommendations. And Microsoft stopped trusting SEDs because they were either not encrypting data or doing so insecurely---not because of concerns over remanence, which is what OP asked about. – DoubleD Oct 30 '19 at 18:14
  • You seem to be commenting in the wrong section. But I think there's room in a comments section to have a broader discussion. Stating questions too narrowly often leads to the right answers to the wrong questions. – Steve Sether Oct 30 '19 at 19:27
  • This doesn't really give me much information. You're just telling me what the term is (I already know the term) and to look it up. I did look at various papers but I couldn't find any specific to EEPROM bulk erasure, only some NAND and NOR flash, magnetic storage, and the occasional paper on SRAM. – forest Oct 31 '19 at 0:05
  • I apologize if I was unclear: This is a very particular niche with a fairly high barrier to entry. You are unlikely to find the information you seek if it is not available through academic sources. If this information is essential to a project, you will likely need to investigate yourself. Basically, I've run into trouble finding data myself related to physical security (remanence and anti-tamper), and I expect you'll have a hard time in the absence of a partnership/affiliation. That said, I don't know if the answer "available data is sparse and/or paywalled" is suitable, so I'm flagging it. – DoubleD Oct 31 '19 at 16:10

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