DEF CON
The 2013 DEF CON edition whose Ryan Clarke-designed playing-card PCB badges intentionally blurred non-electronic identity art, circuit-board construction, continuity testing, role variants, and a cryptographic badge challenge.
Rio Hotel & Casino, Las Vegas, Nevada · United States · 2013
A Ryan Clarke-designed DEF CON 21 badge series built as poker-card printed circuit boards: non-powered identity artifacts whose copper, soldermask, silkscreen, inner-layer metal, role variants, and encoded face-card relationships formed a cryptographic and physical badge challenge.
Lifecycle
WIRED documented the black Uber badge as a more elaborate artifact with a hand-assembled mechanical watch, exposed aging copper, and one-time-pad puzzle relevance.
Challenge writeups document suit symbols, 3-bit binary values, pi/e/Gray-code/LFSR ordering, program text, floor graphics, and badge comparisons feeding the badge-contest solution path.
The DEF CON 21 badge used hidden PCB metal and interconnected paths that attendees could discover with a multimeter, making a non-powered board behave like a puzzle circuit.
Operational history
The catalogue can show a real DEF CON 21 badge-case photo while preserving the full source original and avoiding WIRED, Hackaday, or writeup photos without complete provenance.
The compendium models the badge as a PCB identity and puzzle artifact and avoids firmware, MCU, LED, or battery claims for the standard badge.