CTF Challenges for Disobey 2025

Some of the challenges have a physical side with hardware provided by me. The plan is to have the hardware at the hacklab area in the community village, but it would be nice to have a backup option for placing them at the CTF area. The hardware should fit on one approx 200x80 cm table, requires approx 8 power outlets with minimal power consumption and having at least 2 chairs for the players at the table would be nice.

Master list of challenges

• Analog dreams - a analog osciloscope & rs232 analyzer challenge.
  • Physical component
    • Analog osciloscope
    • Some wires
    • Raspberry pi
• Card dump - a punched card to decode
  • Physical component
    • A real punched card
• Crank it up - Manually clocked 8051 with leds on all bus signals
  • A video will be included later for playing at home
  • Physical component
    • A 8051 system with a pulse encoder wired as clock input, approx 20x30cm
• DDT - CP/M & serial terminal
  • Physical component
    • 14" CRT serial terminal
    • Binder with CP/M manual
• Flag for you
  • 5 bit punched tape
• Hardware crypto - A logic analyzer capture
• Horrible crackme - CP/M 2.2 crackme that is quite horrible
• Lights - 8051
  • 8051 with custom backlit keyboard and LCD, approx 10x20cm
• Like tears in tape - 6bit teletypesetting punched tape
  • Physical component
    • Pieces of genuine punched tape with the flag
• Matrix - 8051 keypad entry
  • Physical component
    • 8051 with a attached keypad, approx 20x30cm
• Ransomware - CP/M 2.2 ransomware lacking a decryptor
• Roped in - 8051 PWN challenge
• Simple crackme - a easyish CP/M 2.2 crackme
• Shape - PDP-8 challenge, tested on real hardware
• Unfiltered crap - USB packet capture