Clear it in 3 steps
Start the environment
Investigate the target
Submit the flag
All challengesIn progress
Programming - Known-Plaintext Attack
Mission
known.txt and ciphertext.b64 are generated from the FLAG injected at startup. Derive the repeating XOR keystream from known plaintext and decrypt RESULT to recover the flag.
Not started
Hints
Hint 1Show
Inspect known.txt and ciphertext.b64 and identify the target record
Hint 2Show
derive the repeating XOR keystream from known plaintext and decrypt RESULT
Hint 3Show
Verify that the reconstructed value has FLAG{...} format