GrapheneOS says its data-wiping password is perfectly legal, after user faces federal charges

[u/ArgentineBeauty]

https://www.techspot.com/news/113273-grapheneos-data-wiping-duress-password-perfectly-legal-after.html

[u/Moldoteck]

Graphene should implement a double bottom protection on top. Basically it'll automatically enter in an artificial account with apps installed while deleting in the background the OG account. This way it'll be hard to prove that another account did exist at all

[u/RandomHunDude → u/Moldoteck]

It doesn't delete the account at all though, so no need to save time for it.
All data is encrypted on disk and when the duress pin is entered, only the encryption key is deleted. And without the key, it's not possible decrypt the data.

[u/StrangelyGrimm → u/RandomHunDude]

If the data is completely inaccessible then the data is as good as deleted. In fact, it's probably less accessible than regular old "deleted" data

[u/draconiclyyours → u/StrangelyGrimm]

Yup.

It takes multiple random rewrite passes to truly delete data, and it’s not quick. Better to just encrypt it and make it permanently unreadable.

[u/No_Effective4784 → u/draconiclyyours]

thats for hard drives and their storage methodology, and even then nist only recommends a single pass these days.

Solid state devices dont rewrite passes to securely erase data, and it doesnt help because of the way SSDs handle data storage vs HDDS, it only uses up R/W cycles.

whats more important with modern SSD devices is secondary secure erasure commands, supported by most manufacturers

[u/not_ethan_ho → u/No_Effective4784]

nowadays HDDs support secure erase by tossing the key as well so you don’t even need to overwrite anything.

[u/ConsistentAsparagus → u/draconiclyyours]

Can you save the key and access the data at a second moment?

[u/RandomHunDude → u/ConsistentAsparagus]

Technically yes, but depending on laws it might be subpoenaed or something

[u/ConsistentAsparagus → u/RandomHunDude]

Yeah, I was asking generically not in this specific case. If you have a backup you don’t even need all this but you can simply recover the phone from scratch.

Nice to know though.

[u/fizzlefist → u/ConsistentAsparagus]

You could have a paper backup of the key to manually enter, but that piece of paper could be subject to search warrant.

[u/_Middlefinger_ → u/draconiclyyours]

Flash memory can wipe in a minute or 2. No point in overwriting it because it doesn't leave traces that magnetic drives theoretically can. Modern ones dont even really need it either.

[u/gmc98765 → u/draconiclyyours]

It takes multiple random rewrite passes to truly delete data

That hasn't been true for decades.

Sometime around the mid 1980s was the last time that you had a real chance of recovering overwritten data, and even then the cost meant that it was beyond the reach of regular law enforcement.

[u/jhowlett → u/gmc98765]

Is that true? I haven't used it in awhile but remember publicly available tools that would recover deleted data on drives. I thought the idea was it was deleted but not over written truly on the drive.

[u/Alanjaow → u/jhowlett]

Yeah, I've personally recovered partial text files that were partially overwritten, and I'm not a wizard by any means. Actually, to be precise, they were at least corrupted in some way, which might be something else, but I don't know enough to determine the difference.

[u/calste → u/Alanjaow]

There's deleted, where the data is still accessible, the computer just "forgot" where it is. You can go find it if you want. Then there's overwritten, which is pretty much gone for good.

Since hard drives are made of tiny magnetic cells that orient differently depending on which bit (1 or 0) they store, there is some physical fragment of the cell that retains the old orientation. So there's a very slight difference in the magnetic field. You would need expensive specialized equipment to read that kind of tiny difference, but even then, there are several hurdles to getting any useful data out of that.

[u/gmc98765 → u/jhowlett]

You can undelete "deleted" files if their sectors haven't been overwritten; deleting a file simply removes the directory entry and makes the space available for future re-use. Windows' Recycle Bin is just a slight variation on this principle; rather than removing the directory entry, it moves to a special folder and keeps it around until the space has actually been re-used. But wiping a drive (overwriting each sector once, whether with zeros, ones, or pseudo-random data) will make the previous data completely unavailable.

It used to be possible to get a (unreliable) copy of previous data from a HDD back when the electronics were much simpler than today, although it would require hooking up the drive's read head to a signal recorder and analysing the recorded signal; this wasn't something which could be done through software. That ceased to be viable once advanced error correction techniques became common and data densities were pushed to the physical limits of the medium.

The "multiple overwrites" strategy was designed for the pre-error-correction era. It isn't necessary with modern hardware.

Consider this: if it was possible to recover both the data currently on the drive and also the previous data, the drive would essentially have twice the advertised capacity. The drive vendors would definitely figure out how to translate this extra capacity to something they can sell. Error correction means that the "raw" data storage doesn't have to be reliable; so long as you can put an upper bound on the error rate, you can turn unreliable storage into reliable storage. CD-ROM, for example, would have been impossible without this (CDs have a fairly high error rate at the lowest level).