crypto-algorithms SKILL.md skillA
crypto-algorithms from hermeticormus/libresecops-claude-code is an agent skill: a SKILL.md folder an AI agent loads when a task calls for it.
mdr add hermeticormus/libresecops-claude-code/crypto-algorithms@git:20260930.71a2663Pins git:20260930.71a2663 in mdr.lock. Pin the fingerprint instead.
- Audit grade
- A, 17 of 17 checks passed
- Kind
- SKILL.md skill
- Repository
- hermeticormus/libresecops-claude-code
- Path
plugins/cryptography-essentials/skills/crypto-algorithms/SKILL.md- Versions recorded
- 2
- Latest version
- git:20260930.71a2663, committed Sep 30, 2026
- First version recorded
- Feb 25, 2026
- Size
- 12,018 bytes
- Repository stars
- 4
- License
- MIT
Algorithm selection guide: a decision tree for cryptographic choices, key size guidelines, modes of operation, and worked examples for authenticated encryption with libsodium, Argon2id password hashing, and Ed25519 signatures. Use when picking an algorithm, mode, or key size.
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 Algorithms > Algorithm selection guide -- when to use what, key sizes, modes of operation, and the decision tree for cryptographic choices. ## Knowledge Base ### The Algorithm Decision Tree ``` What do you need to do? | ├── Encrypt data (make it unreadable without a key) | ├── Symmetric (same key for encrypt/decrypt, fast) | | ├── Prefer: AES-256-GCM or ChaCha20-Poly1305 | | ├── Alternative: XChaCha20-Poly1305 (extended nonce) | | └── Never: ECB mode, DES, 3DES, RC4, Blowfish | | | └── Asymmetric (different keys, slower, for key exchange) | ├── Key exchange: X25519 (ECDH on Curve25519) | ├── Encryption: RSA-OAEP (2048+ bits), or hybrid with X25519 | └── Never: RSA-PKCS1v15 for new systems | ├── Sign data (prove authenticity and integrity) | ├── Prefer: Ed25519 (fast, short signatures, secure) | ├── Alternative: ECDSA P-256, RSA-PSS (3072+ bits) | └── Never: RSA-PKCS1v15 signatures, DSA | ├── Hash data (one-way fingerprint) | ├── General purpose: SHA-256, SHA-384, SHA-512, BLAKE2b, BLAKE3 | ├── Short output: SHA-256 truncated, BLAKE2s | └── Never for security: MD5, SHA-1 (collision attacks exist) | …
Read the whole file at its exact version.
How to install
mdr add hermeticormus/libresecops-claude-code/crypto-algorithms@sha256:2873b4419008fbedThe line at the top of this page pins the label git:20260930.71a2663, 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_p54tizbgiu3xq4c4)
3 badge image fetches in 30 days. What the badge shows.
Versions
The registry has recorded 2 versions of this file, between Feb 25, 2026 and Sep 30, 2026, about one every 218 days. Its first recorded version is graded C and its latest A.
| version | committed | commit | size | audit | |
|---|---|---|---|---|---|
| git:20260930.71a2663 latest | 2026-09-30 | 71a2663 | 12,018 B | A | view · diff |
| git:20260225.4a0a620 | 2026-02-25 | 4a0a620 | 11,691 B | C | view |
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 (12018 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
hermeticormus/libresecops-claude-code · 4 stars · license MIT · pushed 2026-10-04 · branch main
API
GET https://markdownregistry.com/api/v1/artifacts/art_p54tizbgiu3xq4c4 GET https://markdownregistry.com/api/v1/resolve?ref=hermeticormus/libresecops-claude-code/crypto-algorithms GET https://markdownregistry.com/api/v1/blob/2873b4419008fbedcbee906389adc7ab18cefe76343aa5083f02e9ee65dcad88
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.