Crypto

This section focuses on practical cryptography for hacking/CTFs: how to quickly recognize common patterns, pick the right tools, and apply known attacks.

If you're here for hiding data inside files, go to the Stego section.

How to use this section

Crypto challenges reward speed: classify the primitive, identify what you control (oracle/leak/nonce reuse), then apply a known attack template.

CTF workflow

ctf-workflow/README.md

Symmetric crypto

symmetric/README.md

Hashes, MACs, and KDFs

hashes/README.md

Public-key crypto

public-key/README.md

TLS and certificates

tls-and-certificates/README.md

Crypto in malware

crypto-in-malware/README.md

Misc

ctf-misc/README.md

Quick setup

• Python: python3 -m venv .venv && source .venv/bin/activate
• Libraries: pip install pycryptodome gmpy2 sympy pwntools
• SageMath (often essential for lattice/RSA/ECC): https://www.sagemath.org/