ctf-crypto
Provides cryptography attack techniques for CTF challenges. Use when attacking encryption, hashing, signatures, ZKP, PRNG, or mathematical crypto problems involving RSA, AES, ECC, lattices, LWE, CVP, number theory, Coppersmith, Pollard, Wiener, padding oracle, GCM, key derivation, or stream/block cipher weaknesses.
npx skills add ljagiello/ctf-skills --skill ctf-crypto --agent claude-code
Same command for any agent — swap --agent for codex, cursor, copilot.
Weekly change comes from our own snapshots, not the repository page — it measures attention, not adoption.
What it does
The skill is a quick reference for crypto CTF challenges. It presents techniques as one-liners and points to supporting files for full details with code.
How it works
- It lists prerequisites including Python packages (pycryptodome, z3-solver, sympy, gmpy2, hashpumpy, fpylll, py_ecc).
- It provides quick-start commands and links to many sections such as Classic Ciphers, Modern Cipher Attacks, and Modern Cipher Attacks (Part 2 and 3).
- It includes sections for various cipher attack domains (RSA, ECC, PRNG, padding oracle, side-channel analyses, etc.) and mentions tool references (e.g., FeatherDuster, RsaCtfTool) by name.
- It emphasizes that users should refer to specific markdown files (e.g., classic-ciphers.md, modern-ciphers.md, prng.md) for full code examples and detailed procedures.
- It does not specify outcomes; it only enumerates techniques, tools, and high-level methods.
When to use it
- Use when attacking encryption, hashing, signatures, ZKP, PRNG, or mathematical crypto problems involving RSA, AES, ECC, lattices, LWE, CVP, number theory, Coppersmith, Pollard, Wiener, padding oracle, GCM, key derivation, or stream/block cipher weaknesses.
- It is intended as a quick reference toolkit within CTF contexts.
What it can touch
- Tools and commands explicitly named: Python, pip, Azure-like tool names are not specified; specific tool commands mentioned include OpenSSL and RsaCtfTool in examples.
- Allowed tools listed in frontmatter: Bash, Read, Write, Edit, Glob, Grep, Task, WebFetch, WebSearch.
Caveats
- Requires a filesystem-based agent with bash, Python 3, and internet access for tool installation.
- License: MIT.
- It is a reference resource; it does not guarantee success and directs to external files for concrete code.
# 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):** ```bash pip install pycryptodome z3-solver sympy gmpy2 hashpumpy fpylll py_ecc ``` **Linux (apt):** ```bash apt install hashcat sagemath ``` **macOS (Homebrew):** ```bash brew install hashcat ``` **
What does the ctf-crypto skill do?
Provides cryptography attack techniques for CTF challenges. Use when attacking encryption, hashing, signatures, ZKP, PRNG, or mathematical crypto problems involving RSA, AES, ECC, lattices, LWE, CVP, number theory, Coppersmith, Pollard, Wiener, padding oracle, GCM, key derivation, or stream/block cipher weaknesses.
How do I install it?
Run `npx skills add ljagiello/ctf-skills --skill ctf-crypto --agent claude-code` — it drops the skill into your project so the agent can pick it up. Swap the --agent value for codex, cursor or copilot if you use one of those.
Where does this skill come from?
From ljagiello/ctf-skills, a repository with 2,919 stars. We read it straight from the repository tree rather than a submitted listing, so what you see here is what is actually published.
Is a popular skill a good skill?
Not necessarily. Stars measure attention, not adoption — a repository can trend for a week and be abandoned. That is why we show the weekly change from our own snapshots next to the total, instead of a single flattering number.