Like many businesses out there, [Joonas Pihlajamaa’s] employer requires him to change his password every few months. Instead of coming up with a complex, yet easy to remember password again and again, he built a small USB device to do the work for him.
He dismantled an old USB memory stick, fitting it with an ATtiny85 with its required components on a small piece of perfboard. Using the knowledge he gleaned from his previous USB HID tinkering, he programmed the ATtiny to act as a USB keyboard which enters his password for him whenever he plugs it in.
The USB dongle not only types his password in for him, it can generate a new password with a few simple keystrokes whenever he desires. Obviously it merely takes someone getting their hands on his USB stick to compromise security, but it does beat a Post-It under the keyboard any day.
Continue reading to see a short video of his USB password dongle in action, and be sure to swing by his site for more details on how it was all put together.