So, let me welcome Federico who will talk about all your keyboards are built to us.
All right.
Thank you.
So, briefing introduction on me, I've had the privilege of spending nearly my entire career in open source software.
And these days, I'm the product management director for Seth at IBM for Marie Wright hat.
Before that, I was debunked to serve her PM at canonical, and before that, I was known as the system's management star.
The talk has nothing to do with my job.
I'm a manager these days, so as a former and by the developer, this is my definition of fun.
I'm also the co-founder of a smaller and the shop in Boston focused on so-and-or-or in the, and this seemed like an interesting combination of sound security and computers.
So, that would be interesting.
Now, the humorous obligatory disclaimer to all my talks is that we will most likely break some hardware playing with it and it will come out of your pocket.
No liability if you follow your instructions and stop your toll and bring about the end of the universe.
That kind of thing.
But this year, the disclaimer is a different kind altogether.
This talk is all compiled with open sources.
There is no classified material here.
With great power comes great responsibility.
Don't do anything you should not with what you're about to hear.
And don't just obey the law, but since this is a hacking talk, be nice.
Let's get going.
We have a ton of slides, and I don't think we're going to get to demos here, but still getting through all of this is a challenge.
This talk is all about of using our beloved keyboards.
Keyboards have access to the plain text of what we are so carefully encrypting.
They have access to our passwords we hope for hashing.
It follows we obviously want some exploit action.
And there is some pretty wild stuff out there.
One cannot hardly imagine what the big boys and the internal community are capable of when the academics are having this much fun.
Let's start with something light.
Eric Hasselton, an interesting career.
Trained in neurology became a Disney imagining executive.
Then was recruited by General Hayden to run the NSA's R&D department.
An original career to reject if I ever saw one.
So the first movie connection is Disney, but there is a point here.
In Hasselton's book, Great Book, by the way.
Absolutely enjoyable read if you're into tech and espionage.
Details of the discovery of the IBM selectorkin plant in typewriters in US embassies in the eastern block among other stories.
At this point here he is talking about Charles Gandhi, the legendary NSA researcher, and how he got to start in the business.
Spoiler.
It's the movies.
So.
In the movie, FBI agents monitoring Nazi spies in America are remotely being energy from addition to the night.
The room where the spies were planning their next attack.
The intrepid FBI agents were able to decoy the voice signals in the room from reflections of a vibrating speaker in a telephone headset and toward the attack.
The supposedly was in the 1940s.
I still haven't figured out what movie this is.
That's a research project, but that's what Gandhi said.
And 11 year old Gandhi was so impressed that he decided to become an FBI agent and defend the United States.
And then NSA didn't exist in 10 years later.
It did, and so he became an NSA agent.
There is an interesting side story about this movie because.
Can't find it, but.
1940s.
The tempas code were brings us the first attack vector.
We usually call this van Eckfried, which is kind of a misnomer.
But it's a super cool name.
So I'm not advocating we move to something else.
That researcher, Vin van Eck, opened Pandora's box on EM signal emissions with his 1985 paper.
Publishing what cigarette professionals had known since 1940s.
But kept classified.
In the open, it was known that signal leakage existed.
But everybody assumed it would be really hard to get to.
Well, one act demonstrated that it was actually much easier.
So he actually went live on the BBC.
I think this was 1985.
And he demonstrated the attack.
If you go to YouTube and you type BBC Tempest.
And you skip the Shakespeare parts.
You get this video.
In van Eckfried, he exploits the emanation of unshielded CRT screens containing frequency components in the UHF band.
Monitor synchronization pulses are missing and have to be recreated.
So he had to spend the full 15 dollars to make that circuit.
And with that, he could display the resulting feed on a TV of the year.
From about a hundred meters away and up to one kilometer.
People freak out about this every about 20 years I found.
Like the next generation forgets or something like that.
Unclassified NSA history is talk about rediscovery of Tempest as well between the 1940s and the 1950s.
Bell Labs figured it out in 1940s, but the NSA, when they were founded later, they had to rediscover it in the 1950s.
And I think they had some other kind of thing later.
But we don't necessarily care about the intel community.
We care about cyclical freaking out about this in the public sphere.
So we're not going to play the BBC video because we don't have five minutes to do that.
But this gentleman drives around in a van and he manages to read the email that somebody five floors up in writing.
And this is 1980s, so probably it was even legal in England at that point or probably wasn't even an anti-hacking law covering this.
Or maybe he was a friend of the BBC who knows.
But it's a very decent introduction to the topic.
They just drive with an antenna in the van down the street.
And there you go.
You have to watch that separately.
But the Tempest Code Word refers to a classified protection standard for unintended signal emissions linked through EM or other channels.
Most common sources are aware CRT monitors.
Here an exemplary from my retro computing research for those of you to young to know what the CRT monitor is.
This much we know because the code word definition itself has been declassified in 2008.
And you can find it on Wikipedia you find the declassified document.
Much of it is blanked out, however.
But a few interesting things were disclosed.
It was discovered in 1943 at Bell Labs, reading an encrypting machine from across the street in New York City.
Rediscovered in 1951 by the CIA.
Strategies for mitigation include shielding, filtering, and masking.
So shielding with a fire day cage around the thing, filtering, trying to protect the frequencies that you don't want to leak.
Or masking makes so much noise in the same band that you cannot find the right signal.
The eventual resolution to this being instructing facilities to control as zone 200 feet in all directions.
Notably by what we know in the open, this was not a standard dictated for technical reasons.
It was dictated because they didn't think that it was militarily feasible to instruct bases or stations to control more than 200 feet around the area.
It takes people to surveil an area.
So it didn't seem practical to say control a kilometer around your base or something like that.
So this is supposedly a guideline, but it seemed dictated by practical reasons, just as much as physics.
The other recommendation was operating 10 teletypes all at once, which would be masking.
Today we know that that doesn't work, at least not with the kind of analysis that we can do today.
It seemed okay back then. I suppose it was great for teletypes vendors.
Another bit of the declassified memo discloses the red black signal separation requirement that the NSA is in place, which is essentially put the cipher text.
Keep the cipher text separate from the plain text.
Again, because of signal leakage. This is illustrated by this other document.
Another good book, Peter Wright's MI5 memoir. This was a British spy.
In 1960's, UK government wanted to enter the U and the French president and general the Gaulle at the time held a grudge against the British, that was a monumental size, if you know your history.
And so you wanted to keep them out. The foreign office wiretaps the French embassy to understand the French negotiating position.
And as they examine the cipher text coming down the line, they discovered that they don't need to hack it, because the plain text is writing on the same signal of the cipher text much weaker.
So this very faint signal has all that they need, and they find the plain text.
The French cipher was actually good, as far as we know, GCHQ was not able to break it, but they didn't have to.
And the problem here was that the proximity of the two machines, the machine that was controlling the encrypted signal and the machine that was holding the plain text and loud signal leakage.
There you go. The bridge only had to pick up the leaked signal. By the way, it did no good to locate this case. The Gaulle kept the mouth until his death.
The negotiation failed in 1963 and UK joined only a decade later, which is funny, given what's been happening recently.
But history, oh well. Additionally, the declassified code word and three describes signal emanations in other domains, seismic, presumably referring to vibration, but the only title of the section was released.
And acoustic, quaintly termed phenomenon number five, don't ask me why.
So this is actually from the little museum in my IBM office. Here is another target, electric typewriters.
Obviously, here we have the emanation problem, but the interesting bit is the sound emanation. These things make hell of a racket.
Turns out you can figure out what is being typed by listening to a typewriter or teletypes sound.
And the best memo itself indicates this can be done from 100 feet away with a shotgun parabolic microphone.
Another interesting nugget that contrary to expectations, soundproofing a room helps the attacker, because you know where the noise, not the signal.
Something confirmed by others in the open literature, since the range limits for all of these emanation leak attacks are dictated by signal noise, so you can see why.
There is a lot out there about tempest on the internet and some of it is even true, but there is more, and those of you in the room who know cannot tell us.
So there is no point in charging up all the tempest gossip and guessing about that. You can Google it yourself and figure it out.
The other word you want to search for is penning, which unlike tempest has an officially disclosed acronym,
Pobochnia, Electromagnetia, Illucenia, Illavodki, or something like it, which translates to something like unwanted electromagnetic radiation and interference.
Just remember, there is more than in audio, vibration, optical are all coming to the party.
By the way, in Hasselstein's book, he has a ton of footnotes, he is a director at the NSA, so he cannot talk about random junk on Google about tempest.
So he points about, he points to random junk on Google about tempest, which has since all disappeared, but you can find it on archive.
So if you are curious about what Russians declassified and then reclassified or somehow disappeared from the internet, you can find it on archive.org and you can find the URL on Hasselstein's book.
But it's mostly, I mean, maybe 15 years ago, it's mostly about the physics, so don't expect to compute stuff.
I will take revenge of the caps lock for 500 readges.
I must admit, I was disappointed to find no reports of signal leakage from keyboard LEDs, that seemed like an obvious one.
That is unintentional leakage.
There are multiple ex-filtration research papers showing reasonable bandwidth in defeating air-gapped systems by flashing caps lock.
I recall one reaching 56 kilobod.
A character in Neil's defense on scriptonomical, ex-filtrates digger are using caps lock, and in a novel, it also makes extensive use of vanic freaking in its plot, so it's perfect novel for us.
And then there is this. We have an entire industry of pentesters, and the gold standard for them is a keystroke injection tool disguised as a USB drive, which is the rubber duckie.
You know about it unless you have been living under a rock in some outer planet if you are in security.
USB rubber duckie is the original keystroke injection tool in 15 years old, although the hardware has been updated.
It looks like a USB drive to us, it acts like a keyboard when talking to the OS and types of superhuman speed, whatever you tell it to type.
But this is not to talk about the rubber duckie.
This is a talk about signal leakage.
Until 2022, the way you would use a rubber duckie is that you would hack a machine, you would get to a machine, you would put it into a machine, and you would have access to the shell when those are, and then type whatever you want.
As long as the machine is unlocked.
And the rubber duckie would type it for you, so you would just plug it in, it would type at this crazy speed for one second and you're done.
But because it's a keyboard to the OS, you don't have any place to put data that you may want to steal, still.
So USB drive, but it's not good for storage.
So you would send the data to some ugly parts of the internet and retrieve it from there.
Until 2022.
Now, to reduce the price of PC keyboards, IBM delegated the management of the cap state and lights to the host, giving us the site channel keyboards and rather the duckie.
Can now use to expel trade data to its internal storage.
Side channel four decades in the making.
Keystroke reflection relies on only on caps lock, number lock, and scroll lock to establish a data transfer path.
This is something a rubber duckie can now do out of the box.
No more need to connect to our C servers on the far side of the planet to expel data unless there is you want to.
But there is more.
For one simple price of 1999, or never mind.
What is this?
The lower line is an R.S.232 signal.
Straight from the port.
The bottom one is the signal read by Lafrey and Ampress.
Looking at the brightest variation on a modem's DX LED.
Their optical tempest result was a spectacular one if I ever saw a paper.
There's a ring of that title.
This was 2002.
Modens are obviously a thing of the past, but you could read the transmission from across the room or across the street if the window was open.
With some tweaking or a telescope.
One bright spot of their studies that they're testing examined hard disk LEDs and found no IO leakage there.
But wait, there is even more.
The gentleman from Lockheed Martin, previous one, was stopped in the LED category by a team at Ben Gurion University of the Naghe.
The University of the Naghev.
The new glow warm attack display.
Exploids flickering of LEDs in the room connected to a sound speaker.
Or the USB hub the power in it.
To extract spoken audio from up to 25 meters away.
You can see that they're using a telescope to get that signal.
It's not itself a keyboard attack, but leads us to one.
It used to be don't drink and derive, but now it's don't Skype and Type.
A team led by a researcher at the University of Rome,
La Sapienza demonstrated what cool hypothesized and awesome of demonstrated as a possibility.
The audio emanation of a keyboard can be exploited over a phone call or as it turns out, a voice over IP-1.
I must say, like, I like how their code is laid out.
It's not the usual R&D completeness.
It shows a little CS thinking for once.
If you type in Skype, what you type can be recovered with top 5 guessing 91.7% of the time.
But we need to know something to tune the model, something about your typing style and your keyboard,
which leads us to the classic Asimov and Agra Wall study.
By the way, Skype has more advanced in-band filtering now for noise that will get in the way of this.
But this is a 2017 paper and back then you could do it.
At the turn of the millennium, Professor Markus Kuhn at Cambridge published a massive report on CRT emissions.
It is so large for quite some time, I believe, it was a PhD thesis.
This is likely to remain the definitive work on EM emissions, possibly until some NSA work is declassified.
It isn't trying Kuhn as an ex-successor as a spiritual guide of non-classified signal leak researchers.
And a year later, keyboard acoustic emanations was published by IBM Research.
As an over in Agra Wall systematically studied the problem and wrote them meticulously,
meticulously detailed paper answering many core questions.
In their attack, my performance placed near a keyboard from half a meter to 15 meters away.
And sound is sampled with a standard sound card of the period at 44.1KHz.
So sounds like a sound blaster to me.
Neural network is trained to classify a labeled training set of 100 samples per key and tested on a second set.
In two key tests, distinguishing between the keys K and L on a quality keyboard, the system performed flaws.
The model scoring 20 out of 20 and averaging 95% in longer tests.
There are no false positives in the above.
Using their set up, they proceeded to answer core questions.
Well, this instance matter, they tried up to 15 meters away with no decrease in recognition quality.
They placed a microphone beyond the type behind the type list.
In other tests with 30 keys and 300 tests, the model gets the correct key 79% of the time.
Rising 28% in a top three choices set up.
They then tried the model trained on one keyboard on another unit of the same model.
Recovering the text was poor, but the model still yielded significant entropy reduction, potentially an issue for passwords.
In other tests, the type is applied variable force in striking the keys.
The fixed force model floundered, but the new model trained with variable force dataset restored the previous result.
In yet another test, they subjected the variable force model to inputs from multiple typists.
We're free to type in any style they chose.
The quality of classification was adversely affected, but only slight.
Showing the applicability of a model trained by the attacker to a potential victim.
Studying the average sound of individual keys, they narrowed down the fact that the individual location on the keyboard,
given keyboard unit, not its model, not its type is style, and not the keys themselves.
They swap their own key caps and key switches to test this.
Are not what matters.
So you can think of the keyboard plate as maybe a symbol.
And the sound matters where you are hitting the plate.
That's the determining fact.
So lots of retesting in this paper, but it starts from the bottom and builds up.
It's very nice.
And so it looks like the audio signal looks like trauma.
In 2005, you were UC Berkeley team, but led by Lee Juang put the final pieces in place.
They revisit the IBM study and demonstrate the use of unsupervised training by leveraging inherent statistical constraints.
The model is designed to attack passwords and can break five character random passwords in fewer than 20 attempts.
And 80% of 10 character passwords are found if you were than 75.
You would think it's game over already, but it gets worse.
So we're running out of time here, what to.
In 2023, a team of UK researchers designed the demonstrated use of sound from a phone.
And there are a number of studies of this kind that used increasingly first a sound from the phone, which requires hacking the phone.
Then the vibration from the phone, which does not because the vibration sensor of the phone is not privileged.
And basically it gets worse and worse.
We're going to stop here.
There is a recording of the rest on the website of Defcon.
You can see a few other things that are not sound and keywords.
Thank you very much.