PicoCTF-2022 Writeup
  • README
  • Binary Exploitation
    • buffer overflow 1
    • buffer overflow 2
    • buffer overflow 3
    • flag leak
    • function overwrite
    • ropfu
    • stack cache
    • x-sixty-what
  • Cryptography
    • basic-mod1
    • basic-mod2
    • diffie-hellman
    • morse-code
    • NSA Backdoor
    • Sequences
    • substitution
    • Sum-O-Primes
    • Very Smooth
  • Forensics
    • Operation Oni
    • Operation Orchid
    • SideChannel
    • St3g0
    • Torrent Analyze
  • Reverse Engineering
    • Bbbbloat
    • Keygenme
    • unpackme
    • Wizardlike
  • Web Exploitation
    • Forbidden Paths
    • noted
    • Roboto Sans
    • SQLiLite
Powered by GitBook
On this page
  • Challenge
  • Solution
  • Flag

Was this helpful?

Edit on GitHub
  1. Cryptography

basic-mod1

Previousx-sixty-whatNextbasic-mod2

Last updated 3 years ago

Was this helpful?

Challenge

We found this weird message being passed around on the servers, we think we have a working decrpytion scheme. Download the message . Take each number mod 37 and map it to the following character set: 0-25 is the alphabet (uppercase), 26-35 are the decimal digits, and 36 is an underscore. Wrap your decrypted message in the picoCTF flag format (i.e. picoCTF{decrypted_message})

Solution

Run the solution , which directly applies the operations as per the challenge description.

Flag

picoCTF{R0UND_N_R0UND_79C18FB3}

here
script.py