To the left, a breadboard with the ATMega328P being attacked. To the right, the project's display showing multiple ;) smiley faces, indicating that the attack has completed successfully.

Glitching An ATMega328P Has Never Been Simpler

June 3, 2024 by Arya Voronova 4 Comments

Did you know just how easily you can glitch microcontrollers? It’s so easy, you really have no excuse for not having tried it out yet. Look, [lord feistel] is doing glitching attacks on an ATMega328P! All you need is an Arduino board with its few SMD capacitors removed or a bare 328P chip, a FET, and some sort of MCU to drive it. All of these are extremely generic components, and you can quickly breadboard them, following [lord feistel]’s guide on GitHub.

In the proof-of-concept, you can connect a HD44780 display to the chip, and have the victim MCU output digits onto the display in an infinite loop. Inside of the loop is a command to output a smiley face – but the command is never reachable, because the counter is reset in an if right before it. By glitching the ATMega’s power input, you can skip the if and witness the ;) on your display; it is that simple.

What are you waiting for? Breadboard it up and see for yourself, this might be the method that you hack your next device and make it do your bidding. If the FET-and-MCU glitching starts to fail you at some point, there’s fancier tools you can use, like the ChipWhisperer. As for practical examples, [scanlime]’s elegant glitching-powered firmware hack is hard to forget.

Remoticon 2021 // Colin O’Flynn Zaps Chips (And They Talk)

February 3, 2022 by Jenny List 5 Comments

One of the many fascinating fields that’s covered by Hackaday’s remit lies in the world of hardware security, working with physical electronic hardware to reveal inner secrets concealed in its firmware. Colin O’Flynn is the originator of the ChipWhisperer open-source analysis and fault injection board, and he is a master of the art of glitching chips. We were lucky enough to be able to welcome him to speak at last year’s Remoticon on-line conference, and now you can watch the video of his talk below the break. If you need to learn how to break RSA encryption with something like a disposable camera flash, this is the talk for you.

This talk is an introduction to signal sniffing and fault injection techniques. It’s well-presented and not presented as some unattainable wizardry, and as his power analysis demo shows a clearly different trace on the correct first letter of a password attack the viewer is left with an understanding of what’s going on rather than hoping for inspiration in a stream of the incomprehensible. The learning potential of being in full control of both instrument and target is evident, and continues as the talk moves onto fault injection with an introduction to power supply glitching as a technique to influence code execution.