crypto-misuse-reasoning SKILL.md skillA
crypto-misuse-reasoning from annatchijova/skills is an agent skill: a SKILL.md folder an AI agent loads when a task calls for it.
mdr add annatchijova/skills/crypto-misuse-reasoning@git:20260825.8500180Pins git:20260825.8500180 in mdr.lock. Pin the fingerprint instead.
- Audit grade
- A, 17 of 17 checks passed
- Kind
- SKILL.md skill
- Repository
- annatchijova/skills
- Path
crypto-misuse-reasoning/SKILL.md- Versions recorded
- 1
- Latest version
- git:20260825.8500180, committed Aug 25, 2026
- Size
- 9,136 bytes
- Repository stars
- 9
- License
- a license file GitHub does not identify
Judge a cryptographic system by how it is used, not by which primitive it names — because "we use AES-256" says nothing, and almost every real-world break is a misuse (reused nonce, ECB, unauthenticated ciphertext, a padding oracle, a homemade KDF, an accepted downgrade) sitting on top of a perfectly good algorithm. Use whenever crypto is being designed, reviewed, or trusted: "is this encryption secure", "we roll our own", "AES/RSA/we're fine", "how should I encrypt this…
Collected from public GitHub. Every version is saved exactly as it was and never changes. Install it at an exact version with the mdr tool, and every file is checked before it reaches your agent. The main file is checked against the SHA-256 fingerprint recorded here, and the others against the fingerprints GitHub keeps for its source commit. The automatic checks below grade the latest version, and the same checks always give the same file the same grade.
What the file says
# Crypto Misuse Reasoning The name of the primitive is the least interesting fact about a cryptographic system. "We use AES-256-GCM" tells you nothing about whether the nonce repeats, whether the ciphertext is authenticated before it is trusted, whether the key came from a password through a real KDF or a single SHA-256, or whether an attacker can force a downgrade to a weaker path. The algorithm is almost never the break. **The misuse is the break** — and misuse lives in the composition, the parameters, and the surrounding code, not in the cipher. Two symmetric failure modes, and this skill exists to catch both: - **Primitive-name assurance.** "It's AES, it's fine." A green checkmark on the cipher choice while the mode is ECB, the IV is a constant, or the MAC is missing entirely. The strongest cipher in the world, used wrong, is a plaintext leak with extra steps. - **Roll-your-own, including the "small" glue.** Not just inventing a cipher — that is obviously reckless — but the quieter version: a hand-built token format, a custom "encrypt then base64" with no integrity, a password comparison with `==`. The danger is in the parts people do not think of as "crypto." …
Read the whole file at its exact version.
How to install
mdr add annatchijova/skills/crypto-misuse-reasoning@sha256:8a285b829bb34428The line at the top of this page pins the label git:20260825.8500180, which is what most people want. This one pins the sha256 fingerprint of the contents instead, so it survives a label being moved. Either way the exact version is written to mdr.lock, and mdr install downloads and checks those contents again, so it installs them exactly or stops with an error.
[](https://markdownregistry.com/a/art_2tcjlmg2j3iy4l5m)
2 badge image fetches in 30 days. What the badge shows.
Versions
The registry has recorded 1 version of this file, committed on Aug 25, 2026.
Audit of the latest version
- pass: Frontmatter block present
- pass: Frontmatter declares a name
- pass: Frontmatter declares a description
- pass: Size between 200 bytes and 200 KB (9136 bytes)
- pass: No zero-width or bidi control characters
- pass: No instruction hidden inside an HTML comment
- pass: No link to an exfiltration or paste host
- pass: No credential-shaped string
- pass: No instruction to send local credentials anywhere
- pass: No text hidden with inline styles
- pass: No prompt-injection phrasing
- pass: No curl or wget piped into a shell
- pass: No recursive delete of root, home or parent
- pass: No instruction to read or print local credentials
- pass: No base64 blob over 200 characters
- pass: No link to a raw IP address
- pass: No script tag
Source
annatchijova/skills · 9 stars · license a license file GitHub does not identify · pushed 2026-11-02 · branch main
API
GET https://markdownregistry.com/api/v1/artifacts/art_2tcjlmg2j3iy4l5m GET https://markdownregistry.com/api/v1/resolve?ref=annatchijova/skills/crypto-misuse-reasoning GET https://markdownregistry.com/api/v1/blob/8a285b829bb3442881f0b1ab6d5d37407beee30b3eb903bc5357aa52bc35ae50
Your AI assistant does the legwork. You hear about the deals worth your word. Hand yours the standing instructions at modelranch.com and it joins the network that reads files like this one.
Guides: the SKILL.md format and its required fields · what to check before you install a skill · how to pin a skill to an exact version · where to find agent skills · keeping a team on the same skills · which agent file does what.