Did you ever think when stuff like this come out there is some guy at the NSA going "Damn it, there goes another one" as they have know about this and been using if for years :)
Around 1999, I wrote a paper about information leakage from blinking LEDs on devices (one DES link encryption box, used by banks, for example, was sending out plaintext on the LEDs).
I was working for a defense contractor at the time on a classified project, and so, following procedures, we submitted the paper to NSA for approval to publish.
It took a year and a half to approve. [1]
Eventually NSA wrote back and said, "No problem! Go ahead and publish." I kind of wonder what they spent all that time doing.
[1] Actually, it didn't quite happen that way. Our paper was approved for publication very quickly, in only a few weeks; we submitted it to the USENIX Security Symposium, where it was immediately accepted. Later, NSA called us back, and in a panic, demanded we withdraw the paper from the conference. I had to apologize to the conference committee; it was terribly embarrassing, and the delay in publishing was two years.
You been alright, Joe? Ever get the new ideas on certification or guards published you were working on when we talked on Schneier's blog?
I ended up pivoting into trying to figure out how to secure the hardware. Deep submicron effects, supply chain compromises, and Clive's energy gapping recommendation led me to devise concept of putting TCB or monitors in 0.35 micron or up process node that's visually inspectable. Tear down random sample using others if they're clean. Trusted foundries for packaging. SOI for EMF/fault reductions. Bunch of little CPU's like Clive recommended with CHERI or SAFE extensions working over optical links with filtered/masked power.
That's about where past year or two of ideas have led me. Havent built anything: just forwarding concepts to people making guards and such. Curious what others csme up with since most guards have dropped to using Linux on x86 or whatever. Shouldve all been decertified for that shit.
Hi Nick! I'm still working on certification and guards, but in a very early stage company now. Do you know I can predict and (sometimes) control the progress of certification testing of cross domain solutions? That was my PhD.
Now I'm working to rid the world of CDS boxes built on PCs running Linux; I know exactly what you mean. It doesn't matter that you're running SE Linux; the vulnerabilities are lower down in the hardware—Meltdown and Spectre and what's coming after Spectre will go right through your VMs and your policy enforcement and your hardened OS. What's needed is a completely different way of solving the cross domain problem; that's what I've got in prototype.
I've taught Clive's energy gap notion to my students in university classes. That notion is deeply ingrained in what I'm proposing now. Could I talk with you in more detail about that idea of yours for visually inspectable process node?
"Do you know I can predict and (sometimes) control the progress of certification testing of cross domain solutions? That was my PhD."
Sounds more like engineering or process control than ad hoc. That's a good improvement. Esp if someone is assessing time to market or cost-effectiveness.
"that's what I've got in prototype."
Good. Hopefully, everyone does it a bit differently, too, for a security through diversity benefit. Too much monoculture going on even in old high-assurance systems that all built on GEMSOS, SNS, STOP, or LOCK. Three of which were really similar in security enforcement, too.
"I've taught Clive's energy gap notion to my students in university classes. "
He just did another write-up on that with some new channel ideas built-in here:
> one DES link encryption box [...] was sending out plaintext on the LEDs
What? Care to elaborate? Did they just set the LED brightness based on the current octet being encoded or something? But that seems like it's too high frequency to work.
In the early 1990s when we did this research, it was mostly RS-232 devices; the designers did in fact often connect LEDs directly to the serial TXD and RXD lines, which are relatively high voltage and have plenty of drive capability. Garden variety LEDs are plenty fast enough to reproduce bit transitions in the nanosecond range; we measured intelligible signals in the lab well into megabits per second; on real devices in the field, hundreds of kilobits per second.
You're right, the trick wouldn't work so well with modern LVDS levels and speeds, but we examined (at the time) lots of Ethernet NICs with LEDs on them and found no indication there of useful data in the optical region. (It was a different story on the back panel of enterprise Cisco routers....)
Ethernet PHY chips invariably, so far as I've seen, implement a pulse stretcher on the LED output pins for exactly the reason you noted. We found no intelligible optical emanations from any of the—admittedly low-cost—Ethernet devices we tested. But since then, two things have happened: USB and HFT.
There are definite opportunities for the same thing to happen again. I've seen indications of it in a few USB devices.
High Frequency Trading, though, is a whole other can of worms. There, you have FPGAs and ASICs being used to shave nanoseconds off latency, and I wouldn't be a bit surprised to see off-the-shelf gigabit Ethernet PHY chips spurned by fintech specialists designing an extremely specialised piece of hardware to do one job and do it as fast as physics allows.
There's a window of opportunity there (sorry!) for rival HFT firms with a telescope and very high speed photodetector to exploit any incautiously wired-up LEDs connected directly to ASIC signals....
Hint: use a photomultiplier; PIN photodiodes are fast but the transimpedance amplifiers they need are s-l-o-w.
Unfortunately, mitigating a vulnerability can take a long time and might never happen.
When the Imperfect Forward Secrecy paper about weak Diffie-Hellman exchanges came out in 2015, not all systems using the vulnerable groups upgraded immediately, and some systems couldn't be easily upgraded either because they were hard-coded or because they had other software limitations.
The IT security situation in many developing countries is also pretty alarming, for example if you look at the prevalence of old unsupported operating systems and browsers in many places.
Even thinking about traditional emanations issues, the "van Eck phreaking" attacks were publicly demonstrated years ago
And we know that the vendors were notified about Spectre in June of last year and the public was told over a month ago, but pretty much all of us continue to be potentially vulnerable to it in some settings, even more than seven months after vendor notifications!
It can be nice for infosec researchers to think that attackers only gain power and capability by knowing secrets, and that if those secrets are exposed the attackers will lose their capabilities, but a number of people have been pointing out that it doesn't always work that way -- or at least there can be quite a long window of vulnerability.
(However, exposing secrets is definitely an important prerequisite for denying capabilities to attackers.)
The thing I love about HN is that you say something to be amusing and the engineering types (I am one, so I am making fun of myself) always make some logical argument in response. The best part is 90% of the time you learn something!
I was mostly thinking about the narrow problem of widespread use of very old software, and for example Microsoft's visualization of IE6 market share by country after the company got involved in trying to get people to stop using it.
Edit: also, for example, on the Let's Encrypt forums it's somewhat more common for people from developing countries to insist that they have to keep using server software in production that officially went EOL 2 years ago or something. But developing countries absolutely don't have a monopoly on this issue, and I've certainly seen it regularly from users in the United States.
> Did you ever think when stuff like this come out there is some guy at the NSA going "Damn it, there goes another one"
Maybe the opposite. Have other spend time on something that has little practical use given the actual utility instead of spending budget dollars on something else.
If you think that you might want to read the tempest security standard, think about how much extra building compliant facilities cost, and realize that someone who already understood the cost approved the requirement because of a credible threat, or a capability they had and weren't sure if the other team would have.
