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kerckhoffs-principle SKILL.md skillA

kerckhoffs-principle from the-artificer-of-ciphers-llc/skills-from-the-artificer is an agent skill: a SKILL.md folder an AI agent loads when a task calls for it.

Install it, pinned

mdr add the-artificer-of-ciphers-llc/skills-from-the-artificer/kerckhoffs-principle@git:20260530.3e17152

Pins git:20260530.3e17152 in mdr.lock. Pin the fingerprint instead.

Audit grade: A, 17 of 17 checks passed
Kind: SKILL.md skill
Repository: the-artificer-of-ciphers-llc/skills-from-the-artificer
Path: kerckhoffs-principle/SKILL.md
Versions recorded: 1
Latest version: git:20260530.3e17152, committed May 30, 2026
Size: 4,026 bytes
Repository stars: 6
License: MIT

Apply Kerckhoffs's Principle when reviewing security designs, authentication systems, encryption implementations, or any situation where someone relies on keeping an algorithm, method, or system architecture secret for security. Trigger on phrases like "security through obscurity", "we keep the algorithm secret", "don't publish how this works", "our system is secure because nobody knows about it", or any security discussion where the secrecy of the design—rather than the secrecy of a key—is…

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

# Kerckhoffs's Principle

> "In cryptography, a system should be secure even if everything about the system, except for a small piece of information — the key — is public knowledge."
> — Auguste Kerckhoffs, 1883

## The core idea

A secure system should remain secure even if your adversary knows everything about how it works — every algorithm, every protocol, every implementation detail. The only secret should be the **key**: a small, replaceable piece of information that is easy to change if compromised.

Equivalently (Claude Shannon's reformulation): "The enemy knows the system." Design accordingly.

## Why this matters

"Security through obscurity" — keeping the algorithm secret — is a fragile and dangerous strategy:

- **Algorithms leak.** Reverse engineering, insider threats, disgruntled employees, code dumps, patents, academic publications — secrets get out.
- **You can't change an algorithm like you can change a key.** If your secret is the algorithm and the algorithm leaks, you have to redesign your entire system. If your secret is a key and the key leaks, you rotate it.
…

Read the whole file at its exact version.

How to install

The exact contents, by fingerprint

mdr add the-artificer-of-ciphers-llc/skills-from-the-artificer/kerckhoffs-principle@sha256:bf7a3b61126bf531

The line at the top of this page pins the label git:20260530.3e17152, 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.

Badge

[![mdr](https://markdownregistry.com/badge/art_wiyj7m2kqlrzhftv.svg)](https://markdownregistry.com/a/art_wiyj7m2kqlrzhftv)

5 badge image fetches in 30 days. What the badge shows.

Versions

The registry has recorded 1 version of this file, committed on May 30, 2026.

version	committed	commit	size	audit
git:20260530.3e17152 latest	2026-05-30	3e17152	4,026 B	A	view

Audit of the latest version

A 17 of 17 checks passed. Fixed automatic checks with no AI involved, so the same checks give the same answer every run.

pass: Frontmatter block present
pass: Frontmatter declares a name
pass: Frontmatter declares a description
pass: Size between 200 bytes and 200 KB (4026 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

GitHub

the-artificer-of-ciphers-llc/skills-from-the-artificer · 6 stars · license MIT · pushed 2026-11-08 · branch main

API

GET https://markdownregistry.com/api/v1/artifacts/art_wiyj7m2kqlrzhftv
GET https://markdownregistry.com/api/v1/resolve?ref=the-artificer-of-ciphers-llc/skills-from-the-artificer/kerckhoffs-principle
GET https://markdownregistry.com/api/v1/blob/bf7a3b61126bf531a2a766f64b7f768e4921199eb3c7721278702335b6460246

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.

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