ECB Code-Book Attack (Block Recovery)
crypto · medium · +40 XP
Target
GET /api/lab/ecb-101/encrypt?prefix=<str> (returns base64( AES-ECB( prefix || SECRET || pad ) ))
POST /api/lab/ecb-101/submit body {plaintext} (returns flag if secret recovered)
Goal: classic chosen-prefix ECB attack. Vary the prefix length so the boundary between known and unknown sits in a clean block, then brute-force the next byte by trying 256 candidates and matching the ciphertext block. Recover the SECRET ASCII string and submit it.
// AI hint · first is free · then 1 credit or 5 XP
// attack console
/api/lab/ecb-101/
// reuse on the cli
// submit flag
// no solves yet
5 of 17 · crypto