CTF Cryptography Quick reference for crypto CTF challenges. Each technique has a one-liner here; see supporting files for full details with code. Prerequisites Python packages (all platforms): Linux (apt): macOS (Homebrew): Manual install: - SageMath — Linux: , macOS: - RsaCtfTool — (automated RSA attacks) Note: requires libgmp — Linux: , macOS: . Additional Resources - classic-ciphers.md - Classic ciphers: Vigenere (+ Kasiski examination), Atbash, substitution wheels, XOR variants (+ multi-byte frequency analysis), deterministic OTP, cascade XOR, book cipher, OTP key reuse / many-time pad, v…