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

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ctf-workflow/README.md
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Symmetric crypto

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symmetric/README.md
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Hashes, MACs, and KDFs

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hashes/README.md
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Public-key crypto

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public-key/README.md
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TLS and certificates

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tls-and-certificates/README.md
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Crypto in malware

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crypto-in-malware/README.md
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Misc

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ctf-misc/README.md
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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/