Getting it into your agent
One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.
npx skills add hypnguyen1209/offensive-claude --skill crypto-analysisgit clone --depth 1 https://github.com/hypnguyen1209/offensive-claudeWrote this? Show the measurements
A badge with what this costs and how it scanned, read live from this page, so it follows the numbers instead of freezing them. Markdown for a README, HTML for a documentation site or a project page.
[](https://agentmods.dev/skills/hypnguyen1209/offensive-claude/crypto-analysis)<a href="https://agentmods.dev/skills/hypnguyen1209/offensive-claude/crypto-analysis"><img src="https://agentmods.dev/badge/skills/hypnguyen1209/offensive-claude/crypto-analysis/github.svg" alt="Measured on agentmods" height="20"></a>Or the 80×15 button, for a site that already has a row of RSS and ATOM ones. Only the verdict fits; the numbers stay here.
<a href="https://agentmods.dev/skills/hypnguyen1209/offensive-claude/crypto-analysis"><img src="https://agentmods.dev/badge/skills/hypnguyen1209/offensive-claude/crypto-analysis.svg" alt="Reviewed on agentmods" width="80" height="20"></a>- NVIDIA SkillSpector warn
SkillSpector: 1 finding, up to high
These are SkillSpector’s own severities. On a checked sample its high-severity flags on skills were ~96% false positives — a documented command, a public API, a “never do X” rule — so we show them as a caution to read, not a verdict. Why →
- high YARA Match · line 95 YARA rule matched a hack tool or exploit indicator (offensive tools, reconnaissance, privilege escalation, or exploit frameworks).Fix: Remove offensive tool references and exploit code. Legitimate agent skills should not contain penetration testing tools, exploit frameworks, or reconnaissance utilities.
What it costs to keep this loaded
Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.
| Model | Per session | Once invoked |
|---|---|---|
| Fable 5.1 | $0.00050 | $0.02513 |
| Opus 5 | $0.00025 | $0.01256 |
| Sonnet 5 | $0.00010 | $0.00503 |
| Haiku 4.5 | $0.00005 | $0.00251 |
Grade A, and why
crypto-analysis scanned grade A with 0 findings against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured 9d ago.
A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.
Nothing flagged
None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.
How it starts
The opening of the file, as written. The whole thing — 120 lines — stays where its author put it; the contents beside it link to each section on GitHub.
Cryptographic Analysis
When to Activate
- Auditing TLS/SSL/SSH configurations and X.509 PKI (cipher suites, downgrade, protocol flaws)
- Reviewing crypto implementations in source code or captured traffic
- Attacking weak RSA/ECC keys (CTF and real-world weak-key hygiene)
- Recovering ECDSA/DSA private keys from reused or biased nonces (lattice/HNP)
- Exploiting symmetric/AEAD misuse: padding oracles, GCM nonce reuse, key-commitment
- Forging JWT/JOSE tokens (algorithm confusion, none, jwk/jku/kid injection)
- Cracking password hashes and grading KDF strength
- Assessing post-quantum readiness ("harvest now, decrypt later" exposure)
Technique Map
| Technique | ATT&CK | CWE | Reference | Script |
|---|---|---|---|---|
| TLS cipher/protocol downgrade audit | T1600.001 | CWE-326 | references/tls-pki-audit.md | scripts/tls_audit.py |
| Terrapin SSH prefix truncation (CVE-2023-48795) | T1557 | CWE-222 | references/tls-pki-audit.md | scripts/tls_audit.py |
| Marvin/Bleichenbacher RSA timing oracle | T1600 | CWE-208 | references/tls-pki-audit.md | scripts/tls_audit.py |
| X.509 / CT-log shadow-asset discovery | T1589 | CWE-295 | references/tls-pki-audit.md | scripts/tls_audit.py |
| RSA weak-key factoring (Fermat/Wiener/common-modulus) | T1600 | CWE-326 | references/rsa-attacks.md | scripts/rsa_attack.py |
| Coppersmith partial-key & ROCA (CVE-2017-15361) | T1600 | CWE-310 | references/rsa-attacks.md | scripts/rsa_attack.py |
| Hastad broadcast / batch-GCD | T1600 | CWE-326 | references/rsa-attacks.md | scripts/rsa_attack.py |
| ECDSA nonce reuse key recovery | T1552.004 | CWE-323 | references/ecc-nonce-attacks.md | scripts/ecdsa_lattice.py |
| Biased-nonce lattice/HNP (Minerva, PuTTY CVE-2024-31497) | T1552.004 | CWE-1241 | references/ecc-nonce-attacks.md | scripts/ecdsa_lattice.py |
| Psychic signature (0,0) (CVE-2022-21449) | T1606.001 | CWE-347 | references/ecc-nonce-attacks.md | scripts/ecdsa_lattice.py |
| CBC padding oracle (byte-by-byte decrypt) | T1040 | CWE-209 | references/symmetric-aead.md | scripts/padding_oracle.py |
| AES-GCM nonce reuse "forbidden attack" | T1040 | CWE-323 | references/symmetric-aead.md | scripts/gcm_nonce_reuse.py |
| AEAD key-commitment / invisible salamanders / partitioning oracle | T1606 | CWE-347 | references/symmetric-aead.md | scripts/gcm_nonce_reuse.py |
| JWT algorithm confusion RS256→HS256 (CVE-2024-54150) | T1606.001 | CWE-347 | references/jwt-jose.md | scripts/jwt_forge.py |
| JWT alg=none / jwk / jku / kid injection | T1606.001 | CWE-347 | references/jwt-jose.md | scripts/jwt_forge.py |
| Hash identification & GPU cracking | T1110.002 | CWE-916 | references/hash-pq.md | scripts/hash_triage.py |
| Weak KDF / fast-hash password storage | T1110.002 | CWE-916 | references/hash-pq.md | scripts/hash_triage.py |
| Post-quantum / HNDL exposure review | T1600 | CWE-327 | references/hash-pq.md | scripts/tls_audit.py |
What ships with it
13 files beside SKILL.md in the same directory: the scripts, references and assets a skill reads on demand. Not counted in the per-session cost; read them before you install if any of them is executable.
- references/ecc-nonce-attacks.md 7.1 KB
- references/hash-pq.md 7.1 KB
- references/jwt-jose.md 7.7 KB
- references/rsa-attacks.md 7.0 KB
- references/symmetric-aead.md 6.9 KB
- references/tls-pki-audit.md 6.7 KB
- scripts/ecdsa_lattice.py 8.1 KB runs code
- scripts/gcm_nonce_reuse.py 5.8 KB runs code
- scripts/hash_triage.py 4.8 KB runs code
- scripts/jwt_forge.py 8.8 KB runs code
- scripts/padding_oracle.py 7.2 KB runs code
- scripts/rsa_attack.py 10 KB runs code
- scripts/tls_audit.py 8.8 KB runs code
What this file has done since we first saw it
Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.
- 9d ago First seen · 120 lines · 50 tokens per session scan A 4fdb7bfc9cc0
crypto-analysis is a skill published in the GitHub repository hypnguyen1209/offensive-claude (357 stars, last pushed 23d ago), licensed MIT. It adds 50 tokens to every session and 2,513 once invoked, about $0.0003 per session on Opus 5. A static security scan graded it A with 0 findings. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-30.
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