7th university player · 17th overall · 15th university team · 36th team overall.
Known-plaintext attack on a Hill/affine cipher
AES with SubBytes removed → the whole cipher is linear
8-bit LFSR keystream, brute-force the IV
Redacted LFSR feedback, recovered from a known pt/ct pair
Monoalphabetic substitution, cracked by crib-dragging
Caesar cipher
Columnar transposition
Vigenere with a drifting shift
Message hidden in an audio spectrogram
"Redacted" PDF with a live, copy-pasteable text layer
Flag split across base64-encoded PNG metadata fields
9 images concatenated into a single .jpg file
Reading "RAM" out of a CSS-only x86 emulator
Self-obfuscated Python, deobfuscated by hooking exec()
Datalog injection into a Biscuit auth token
robots.txt points straight at the flag
Binary maze of /l and /r routes
Bypassing a faked Function.prototype.toString
Smuggling unsafePerformIO past a single-pass string filter
Transposed piano notes at the end of a song