This isn't stand-up-to-state-actors security. This is keep-state-actors-from-noticing security. They know you're guilty, they'll get it. The XKCD version of password cracking works no matter how secure your hardware.

But while states realistically can crack most anything it doesn't mean they can crack *every*thing. There are simply too many flash drives crossing the border every day.

But there is a big flaw I see: 8gb. You're carting around an 8gb flash drive these days??

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tptacek 3 hours ago | parent | next [-]

We're talking about exactly the same threat. What I'm pointing out is that state adversaries won't have to "notice" this; all they'll have to do is plug the device into a standard commercial forensics scanner product --- and we're stipulating that they're plugging the device in already (else what does it matter what bits are on it).

They pay other people to notice this stuff for them!

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whizzter 2 hours ago | parent | next [-]

I think part of the entire design is that it's quite hard to detect.

1: Reads/Writes are just routed to a COTS SD-card. 2: Unless the (correct?) password is detected in the write-data that starts the disconnect procedure.

The only way to detect it from what I can see is to profile writes then append a "password:" string multiple times to measure the write-delay, only works if the CPU cost is large enough to overtake the SD-card measurably and some constant-time optimizations should make it more or less undetectable.

It's a clever design and I think it should be possible to optimize to become more or less unrecognizable.

	▲	tptacek 2 hours ago \| parent [-]
		Can you flesh that out? If I've missed something and oversimplified the design here, I'd want to clarify that!

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awesome_dude 2 hours ago | parent | prev [-]

> They pay other people to notice this stuff for them!

Money, even at state level, is not some infinite resource (and neither is time).

States put effort into what they consider worth investigating - no state strip searches every incoming traveller, and goes through every item in their possession - it's possible for them to do, and if they did they'd find a hang of a lot more contraband, but it's costly, time consuming, and politically risky.

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mediaman 2 hours ago | parent [-]

He's saying they just plug your USB stick into some gizmo sold to the state, and it's going to find enough to escalate it.

If the idea is that there's no point in encrypting anything on a USB stick, and you just hope they don't look at it at all, sure.

But there is no threat model here that includes "check the USB stick" and does not automatically lead to finding and breaking "hidden" content.

	▲	NetMageSCW 2 minutes ago \| parent [-]
		Try to explain how the hidden content would be found? It effectively doesn’t exist until the password is in place. It isn’t hidden, it isn’t connected at all.

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giancarlostoro 3 hours ago | parent | prev [-]

> The XKCD version of password cracking works no matter how secure your hardware.

Lavabit would like to enter the conversation.

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ThePowerOfFuet 3 hours ago | parent [-]

The xkcd approach worked in that case; the wrench in that case was legal, not physical, but boy would it have hurt nonetheless.

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giancarlostoro 3 hours ago | parent [-]

He deleted everything ultimately. He printed it out in ultra tiny font in order to comply, but it was nearly impossible for law enforcement to use it. The FBI never decrypted the files.

	▲	tptacek 43 minutes ago \| parent \| next [-]
		It's hard to tell if you're being serious here. At the end of the day, Lavabit's security came down to... the FBI's inability to read an ultra tiny font? That's not the actual story (like, that happened, but all it did was provoke the DOJ), but it's remarkable to see someone cite that as a success for Levison.
	▲	akerl_ 2 hours ago \| parent \| prev [-]
		What about the other Lavabit users whose data he had handed over previously, before deciding to say no?