Thermal Camera Plus Machine Learning Reads Passwords Off Keyboard Keys

May 4, 2023 by 43 Comments

An age-old vulnerability of physical keypads is visibly worn keys. For example, a number pad with digits clearly worn from repeated use provides an attacker with a clear starting point. The same concept can be applied to keyboards by using a thermal camera with the help of machine learning, but it also turns out that some types of keys and typing styles are harder to read than others.

Researchers at the University of Glasgow show how machine learning can pull details from thermal images like these quickly and effectively.

Touching a key with a fingertip imparts a slight amount of body heat, and that small amount of heat can be spotted by a thermal sensor. We’ve seen this basic approach used since at least 2005, and two things have changed since then: thermal cameras gotten much more common, and researchers discovered that by combining thermal readings with machine learning, it’s possible to eke out slight details too difficult or subtle to spot by human eye and judgement alone.

Here’s a link to the research and findings from the University of Glasgow, which shows how even a 16 symbol password can be attacked with an average accuracy of 55%. Shorter passwords are much easier to decipher, with the system attacking 6 and 8 symbol passwords with an accuracy between 92% and 80%, respectively. In the study, thermal readings were taken up to a full minute after the password was entered, but sooner readings result in higher accuracy.

A few things make things harder for the system. Fast typists spend less time touching keys, and therefore transfer less heat when they do, making things a little more challenging. Interestingly, the material of the keycaps plays a large role. ABS keycaps retain heat far more effectively than PBT (a material we often see in custom keyboard builds like this one.) It also turns out that the tiny amount of heat from LEDs in backlit keyboards runs effective interference when it comes to thermal readings.

Amusingly this kind of highly modern attack would be entirely useless against a scramblepad. Scramblepads are vintage devices that mix up which numbers go with which buttons each time the pad is used. Thermal imaging and machine learning would be able to tell which buttons were pressed and in what order, but that still wouldn’t help! A reminder that when it comes to security, tech does matter but fundamentals can matter more.

a 3D printed box with a Terminator head watching a camera

Machine Vision Helps You Terminate Failing 3D Print Jobs

April 25, 2022 by 13 Comments

If you’re a 3D printer user you’re probably familiar with that dreaded feeling of returning to your printer a few hours after submitting a big job, only to find that it threw an error and stopped printing, or worse, turned half a spool of filament into a useless heap of twisted plastic. While some printers come with remote monitoring facilities, [Kutluhan Aktar]’s doesn’t, so he built a device that keeps a watchful eye on his 3D printer and notifies him if anything’s amiss.

a 3D printed box with a Terminator head watching a cameraThe device does this by tracking the movement of the print head using a camera and looking for any significant changes in motion. If, for example, the Y-axis suddenly stops moving and doesn’t resume within a reasonable amount of time, it will generate a warning message and send it to its owner through Telegram. If all three axes stop moving, then either the print is finished or some serious error occurred, both of which require user intervention.

The camera [Kutluhan] used is a HuskyLens AI camera that can detect objects and output a set of 3D coordinates describing their motion. A set of QR-like AprilTags attached to the moving parts of the 3D printer help the camera to identify the relevant components. The software runs on a Raspberry Pi housed in a 3D-printed enclosure with a T-800 Terminator head on top to give it a bit of extra presence.

[Kutluhan]’s description of the project covers lots of detail on how to set up the camera and hook it up to a Telegram bot that enables it to send automated messages, so it’s an interesting read even if you’re not planning to 3D print something to check on your 3D printer. After all, software like Octoprint has many similar features, but having an independent observer can still be a good safety feature to prevent some types of catastrophic failure.

Continue reading “Machine Vision Helps You Terminate Failing 3D Print Jobs” →

Retro Useless Clock Eventually Shows You The Time

June 3, 2021 by 8 Comments

It’s true; hackers like clocks. And hackers like useless machines. But would they like an intersection of the two? We’re thinking yes, probably, though we would argue that this QR clock was at no point fully useless. Yes, a QR clock as in, whip out your phone and, ignoring the conveniently-available phone time, open the bar code reader so you can check the time on this thing. So, it’s semi-useless. But at least it doesn’t detect cameras and then hide the QR code. That would be evil.

This project started life as a display piece for the hex wall down at [megardi]’s hackerspace, but, state of the world being what it is, [megardi] hasn’t made it down there yet. And meanwhile this little guy was looking cuter and cuter, so [megardi] decided to make him more useful and freestanding. The ESP32 inside gets the official time from NIST and displays it on the 1.5″ OLED screen. It also has a single alarm now, along with some other non-QR code clock faces that display the time in various ways.

We really like the look of this clock. Honestly, with those uniform tics around the edge, it sort of reminds us of the doomsday clock — you know, the ‘minutes to midnight’ quarter clock face that shows the current perceived threat level of how close we are to destroying the world with the technologies we’ve created. That clock is kind of cute, too, which is a little bit weird considering what it represents.

Speaking of our delicate planet, here’s a gorgeous little Earth clock that casts a shadow on whatever slice of the planet is currently shrouded in darkness.

Totally Useless Coffee Dispenser Is Anything But

April 5, 2021 by 15 Comments

Good coffee is nice to have, sure, but frankly, caffeine is caffeine and we’ll take it any way we can get it. That includes freeze-dried, if that’s all you’ve got. We won’t judge anyone for their taste in caffeinated beverages, and to call this coffee dispenser ‘totally useless’ is just patently untrue. It clearly has a use, and even if you don’t like freeze-dried coffee, you could sacrifice one jar worth of Nescafe and fill it with Skittles or anything else that will fit in the little collector basket.

In this machine, the cup is the trigger — the 3D-printed plate underneath activates a micro switch embedded in the scrap wood base, and this triggers a micro:bit around back to actuate the stepper motor that twirls the collector basket around. Although [smogdog] has provided all the files, you’d have to come up with your own connector to suspend the thing over the cup and carve your own base.

We love it when we can see what a machine is doing, so not only is it useful, it’s beautiful. And it worked, at least for a little while. For some reason, it keeps burning out stepper motors. Check it out in proof-of-concept action after the break.

We’ve seen the Micro:bit do a lot, and this pinball machine is among the most fun.

Continue reading “Totally Useless Coffee Dispenser Is Anything But” →

Complicated And Useless Cancel Each Other Out

March 3, 2021 by 11 Comments

We all know what it means to procrastinate, but what about actively spending time building a useless machine? You have undoubtedly seen the ornamental boxes with a tempting little toggle switch on the top. When you inevitably flip the switch, an actuator pops out from one half of the enclosure with the sole purpose of undoing its own power switch. [Paz Hameiri] took it a step further by adding some [Rube Goldberg] flavor, and with the help of a microcontroller, his levers take their sweet time powering themselves down. (Video after the break.)

We didn’t find any code or diagrams for the project, but if you know the useless machine’s internals, it shouldn’t be any trouble to recreate one for your desk. The most significant design factor is that the switches. Their contacts must be wired in parallel so that the controller has power as long as one is active. How would you spice up the useless machine?

Even though these are called useless machines, they serve the purpose of decoration, conversation-starting, or a way to show off your woodworking and programming skills.

Continue reading “Complicated And Useless Cancel Each Other Out” →

A Clap-Activated Machine For All Your Applause Needs

November 29, 2020 by 6 Comments

Applause is greatly revered as a symbol of warmth and adoration from a crowd. TV shows that film in front of a live audience often cue their audiences to clap in order to generate the desired auditory atmosphere. Of course, you don’t have to rely on squishy humans to do all the work. [Dillon] built a machine of dubious utility – one which generates mechanical applause when activated by the sound of clapping. (Video, embedded below.)

Somewhat unsurprisingly, the project was built for a Useless Machine contest, but that doesn’t diminish its value as a learning exercise. An Arduino runs the show, using a microphone module to listen out for loud noises such as claps. If two claps are detected in the nominated timeframe, the machine begins to flash its “APPLAUSE” lights and clap its hands. The Arduino achieves this with the help of a relay, which switches on a motor spinning a belt-driven cam which seperates the hands. The hands are then pulled back together to clap via a length of stretchy bungee cord.

With an incredibly noisy drivetrain and somewhat amateur clapping ability, the sound coming from the machine isn’t exactly recognisable as “applause”. However, it’s a start, and it remains the best clapping machine we’ve seen this decade. If you’ve got your own under construction, consider dropping us a line. And if all this has you waxing nostalgic for the vintage Clapper circuit, you can always build one of those, too.

Continue reading “A Clap-Activated Machine For All Your Applause Needs” →