Eric Evenchick
Author of the Hackaday report used for the non-electronic-electronic badge framing and PCB construction details.
SourceDEF CON 21 · United States · 2013
DEF CON 21 Badge
Non-electronic PCB playing-card puzzle badge
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.
EventDEF CON 21
SeriesDEF CON
LocationRio Hotel & Casino, Las Vegas, Nevada
CountryUnited States
Image Provenance
- Asset
- optimized WebP from Flickr documentary photo
- Status
- licensed original photo
- Source
- populated defcon 21 badge case
- License
- Creative Commons Attribution 2.0 Generic
- Attribution
- Openfly, Flickr
- Notes
- Original 1840x3264 Flickr photo downloaded from the photo page's original-size asset and preserved in Public/images/source. The published WebP delivery asset is auto-oriented, metadata-stripped, resized to 902x1600, and otherwise kept as the real CC BY 2.0 documentary photo. The Flickr title identifies the image as a populated DEF CON 21 badge case; this is not generated content or a placeholder. The published badge.gallery delivery file is an optimized WebP generated from the rights-cleared local derivative/source with metadata stripped, WebP quality 82, and a maximum side cap of 1600 pixels when the source is larger; upstream source URL, license, and attribution remain unchanged.
People
Authors & Credits
Ellen
The public DEF CON 21 badge-contest writeup thanks Lost and Ellen for the challenge context.
SourceRyan Clarke / LostboY / LosT
WIRED, Hackaday, and Malwarebytes identify Ryan Clarke as the DEF CON 21 badge designer and opening-ceremony badge presenter.
SourceMLF / CK / Decrement / Elegin / Beeker
The writeup credits the solving and documentation team for the DEF CON 21 badge-contest walkthrough.
SourceWhy It Mattered
It records an important North American counterpoint in the DEF CON badge lineage: the badge was intentionally not an electronic gadget, yet still used PCB manufacturing, continuity probing, visual cryptography, social comparison, and event-space clues as hackable surfaces.
Hardware
Contemporary sources describe poker-card badge artwork fabricated as PCBs using silkscreen, soldermask, copper, and hidden inner-layer metal traces. WIRED documented human, press, vendor, speaker, goon, and black Uber variants, with more than forty variations across designs and mechanical-watch work in the Uber badge.
Software & Apps
No firmware is claimed for the standard badge. The puzzle surface was physical and textual: continuity testing with a multimeter, encoded symbols, card relationships, DEF CON program clues, floor graphics, and web-hosted challenge material.
Lore
The DEF CON 21 theme leaned into tradition, time, playing cards, famous hacker face cards, hidden Easter eggs, and a one-time-pad Uber-badge puzzle that WIRED reported was solved months after the conference.
Lifecycle
Add-ons & Upgrades
black-badge artifact
historical
Mechanical Uber badge watch
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.
Source
event challenge
historical
Playing-card crypto matrix
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.
Source
physical challenge
historical
Continuity-probed PCB puzzle
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.
SourceOperational history
Issues & Camp Impact
image provenance
note
The published DEF CON 21 image is an optimized WebP derivative of Openfly's CC BY 2.0 Flickr photo titled populated defcon 21 badge case.
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.
- Confidence
- source-backed
- Status
- licensed original replacement applied
- Timeframe
- current catalogue build
- Source note
- Flickr photo-page title and CC BY 2.0 license metadata, plus badge.gallery image policy.
non-electronic scope
note
DEF CON 21's standard badges were intentionally described as non-electronic-electronic rather than powered electronic gadgets.
The compendium models the badge as a PCB identity and puzzle artifact and avoids firmware, MCU, LED, or battery claims for the standard badge.
- Confidence
- source-backed
- Status
- documented
- Timeframe
- DEF CON 21 badge pass
- Source note
- Hackaday DEF CON 21 report and WIRED badge reveal.
Resources
DEF CON 21 badge-case Flickr photo
licensed photo · Flickr source for Openfly's CC BY 2.0 original photo titled populated defcon 21 badge case.
DEF CON 21 event archive
event page · Official DEF CON archive source for DEF CON 21 event context, contest results, press archive, and post-event conference material links.
DEFCON 21 Badge Contest writeup
writeup · Winning-team writeup documenting program clues, badge matrix analysis, badge symbols, binary ordering, floor graphics, and puzzle-solving flow.
DEFCON 21 attendee report
article · Attendee report documenting opening-ceremony badge discussion, Ryan Clarke / LostboY attribution, and puzzle interaction framing.
Hackaday at DEF CON 21
article · Contemporary field report naming Ryan Clarke as badge designer and documenting the non-electronic-electronic PCB playing-card design, copper/soldermask/silkscreen artwork, XOR gate, and crypto challenge.
WIRED DEF CON 21 badge reveal
article · Detailed contemporary source for role variants, PCB inner-layer continuity clues, poker-card artwork, famous-hacker face cards, Uber mechanical watch, Easter eggs, and Ryan Clarke design quotes.
Sources
DEF CON: DEF CON 21 Hacking Conference
Retrieved 2026-05-15 · Official event archive source for DEF CON 21 conference context, contest archive links, press archive, and post-event material release.
Elegin / MLF: DEFCON 21 Badge Contest
Retrieved 2026-05-15 · Challenge writeup source for badge matrix interpretation, symbol sets, 3-bit binary ordering, program and floor-graphic clues, and solved puzzle flow.
Flickr: populated defcon 21 badge case
Retrieved 2026-05-15 · CC BY 2.0 original photo source by Openfly identifying the object as a populated DEF CON 21 badge case; used for image provenance, not hardware specification.
Hackaday: Hackaday At DEF CON 21
Retrieved 2026-05-15 · Contemporary source for Ryan Clarke designer attribution, non-electronic-electronic framing, PCB playing-card construction, visible copper/soldermask/silkscreen layers, XOR gate, and crypto challenge.
Malwarebytes Labs: DEFCON 21: An Odyssey
Retrieved 2026-05-15 · Attendee report source for badge-line experience, Ryan Clarke / LostboY opening-ceremony attribution, and attendee-facing puzzle framing.
WIRED: Hidden Circuits and Handmade Clockwork: The Striking Intricacies of Def Con Badges
Retrieved 2026-05-15 · Contemporary source for PCB inner-layer metal clues, role badge types, over-forty design variations, poker-card/famous-hacker motifs, Uber watch construction, and Ryan Clarke quotes.