Leon Jacobs / leonjza
Author of the first-hand 2017 RFCat challenge writeup and publisher of the released challenge-client and server gist.
SourceBSides Cape Town 2017 · South Africa · 2017
BSides Cape Town 2017 RFCat Badge
two-part ESP and CC1111 RF challenge badge
A BSides Cape Town 2017 badge system documented as two separate physical badges: a black flux-capacitor badge with an ESP chip and a red RF badge with a CC1111 RFCat-compatible radio, USB port, and button.
SeriesBSides Cape Town
LocationCentral Park Building, Black River Park, Cape Town
CountrySouth Africa
People
Authors & Credits
Mike Davis / ElasticNinja
The writeup says ElasticNinja invited the author to build the RFCat challenge after discussion of adding CC1111 hardware to the badges.
SourceSensePost
Publisher of the first-hand BSides Cape Town 2017 RFCat challenge article used as the core source trail.
SourceWhy It Mattered
It adds a second strong South African BSides hardware record and preserves an African RF challenge badge where conference-badge hardware, RFCat tooling, and event-game infrastructure were deliberately tied together.
Hardware
The first-hand SensePost writeup describes a black flux-capacitor badge with a 2AL3B ESP chip, WiFi capability, power-bank wiring, USB charging cable, and rear buttons, plus a red RF badge with a CC1111 RFCat-compatible chip, USB port, and button.
Software & Apps
The released gist preserves RF chat-client and challenge-server code using RFCat, 868 MHz settings, sync words, FSK and ASK/OOK modulation, a challenge server running with a Yardstick One, periodic hints, player-state persistence, XOR/base64 final payloads, and Back to the Future themed progress gates.
Lore
The challenge asked attendees to discover RF settings from the flux-capacitor art or by sniffing, join the badge radio network, solve an 88-miles-an-hour stage, decode a hint using the key `fourth dimensionally!`, and send an unlock payload toward a physical challenge box.
Lifecycle
Add-ons & Upgrades
badge app
source-backed
RFCat broadcast chat client
Released client code implemented a half-duplex RF broadcast chat system for badges using RFCat, 868 MHz operation, sync words, modulation settings, queues, and retransmission.
Source
badge component
source-backed
Black flux-capacitor ESP badge
The 2017 badge system included a black flux-capacitor badge with a 2AL3B ESP chip, WiFi capability, power-bank wiring, USB charging path, and rear buttons.
Source
badge component
source-backed
Red CC1111 RFCat RF badge
The red RF badge carried a CC1111 RFCat-compatible chip, USB port, button, and exposed rear contacts, becoming the radio surface for the 2017 challenge.
Source
event game
source-backed
Challenge server and unlock flow
The challenge server used distinct RF settings, periodic hints, player-state persistence, 88-miles-an-hour and 1.21-gigawatts stages, and an XOR/base64 unlock payload for the final box.
SourceOperational history
Issues & Camp Impact
challenge-author caveat
note
The challenge author states that he did not have a badge before the conference and used Yardstick One hardware to mimic the badge RF environment during development.
The dossier distinguishes the badge hardware from the off-badge development and challenge-server test setup.
- Confidence
- first-hand writeup
- Status
- documented
- Timeframe
- 2017 challenge preparation
- Source note
- SensePost BSidesCPT17 RFCat challenge writeup.
hardware-detail caveat
note
The current public source describes visible badge components and challenge behavior, but does not recover schematics, board files, bill of materials, firmware for the ESP badge, or a full original badge-team build writeup.
The record preserves the source-backed two-part badge without inventing component-level details that are not public in the recovered sources.
- Confidence
- source-backed but incomplete
- Status
- needs original badge-team archive
- Timeframe
- 2017 badge archive pass
- Source note
- SensePost writeup and released RFCat challenge gist.
missing rights-cleared image
note
No local BSides Cape Town 2017 badge image has been added because the public writeup photos have not been paired with an explicit reuse license, attribution, and processing notes for catalogue publication.
The record stays image-free rather than copying SensePost or blog imagery without complete provenance.
- Confidence
- local project policy
- Status
- needs licensed original replacement
- Timeframe
- current catalogue build
- Source note
- badge.gallery image policy and BSidesCPT17 RFCat challenge writeup.
Resources
BSides CPT 2017 RFCat challenge sources
source · Public gist containing the RF chat client, challenge server, XOR helper, RF parameters, hint flow, and expected solve path for the badge challenge.
BSides Cape Town 2017 event listing
event listing · Secondary event-context listing for the December 2, 2017 Cape Town date, venue, and BSides Cape Town website pointer.
BSidesCPT17 RFCat challenge writeup
project page · First-hand SensePost writeup documenting the two-part 2017 badge hardware, CC1111/RFCat RF badge, ESP flux-capacitor badge, RF chat idea, and challenge flow.
Sources
GitHub Gist: BSides CPT 2017 - RFCat Challenge Server and Client Sources
Retrieved 2026-05-15 · Primary released challenge-code source for RF settings, challenge-server behavior, player-state persistence, periodic hints, XOR helper, and intended badge solve path.
Security.World: BSides Cape Town
Retrieved 2026-05-15 · Secondary event-context source for date, Cape Town venue, and the public 2017 event listing.
SensePost: building the bsidescpt17 rfchallenge
Retrieved 2026-05-15 · First-hand source for the 2017 two-part badge hardware, flux-capacitor ESP badge, red CC1111 RF badge, RFCat challenge, RF chat behavior, challenge box, and solve flow.