The Iced Gems Biscuit Badge | SINCON

The Idea

I was brainstorming with the fabulous crew at the SINCON conference about a badge for their 2024 edition. Our last year's SINCON badge was a huge hit which came in the Khong Guan building design in Singapore and the CTF on it unlocked floor lights based on correct flags.

For the 2024 edition, it'd be a CTF badge with some big upgrades on it. First - we moved from the ABOV microcontroller to Nuvoton for better support and reliable supply. Second, we'd introduce UV-printed artwork to this year's edition.

Naturally, I was expecting to see another heritage building theme but I was quickly surprised and intrigued by the idea of an iced gems biscuit design.

The Design

The Iced Gems Biscuit could use some sprinkle toppings and that would come from the SMD LEDs mounted upside down from the backside.

Instead of glowing the LEDs through PCB material, we drilled tiny holes to bring out the bright sparkling effects.

4 SMD LEDs would glow the bottom right side SINCON logo by default. And 8 SMD LEDs would be dedicated to CTF and unlocked by CTF flags. Micro-USB for CTF interfacing, a couple of coin cells and all the components are housed on the backside of the badge.

Putting all that into production and we get...

UV Printing The Artwork

We made two design variations for the icing top part. Purple-blue for the attendees and Red-Blue for the crew and speakers.

The Working

Turning on the slide switch glows the SINCON conference logo on the bottom right side by default. The rest of the LEDs if soldered also glow for a couple of seconds to give a cool show-off of all things unlocked. The correct CTF flags unlock and do a cool animation for LEDs.

Attendees were free to choose and play the CTF in any order they wanted for a challenge pool of a variety of Crypto and Stegano challenges. At the conference, we hosted a soldering village to help attendees solder their own LEDs in the colours they want and personalise their badges.

Instructions on how to solder the badge as well as play at CTF are here.

The badge remembers the flags even if the cable is disconnected. Happy Hacking!