Description
A basic substitution cipher using punctuation clues can be quickly decoded with online tools. Extract the flag from the plaintext paragraph.
Setup
Feed the ciphertext into quipqiup.com (or another substitution solver).
Copy the generated plaintext and look for picoCTF{...} near the end.
Solution
- Step 1Let quipqiup do the heavy liftingBecause the text retains spaces/punctuation, an automated solver recovers the entire sentence without manual tweaking.
- Step 2Record the flagThe final sentence explicitly states the flag in clear text.
Flag
picoCTF{FR3QU3NCY_4774CK5_4R3_C001_7AA384BC}
Most picoCTF substitution challenges are intentionally solver-friendly to introduce the concept.