crypto-protocol-diagram

An agent skill by trailofbits, from trailofbits/skills. Tags: analysis, crypto, diagrams, documentation.

What it does

Extracts protocol message flow from source code, RFCs, academic papers, pseudocode, informal prose, ProVerif (.pv), or Tamarin (.spthy) models and generates Mermaid sequenceDiagrams with cryptographic annotations. Use when diagramming a crypto protocol, visualizing a handshake or key exchange flow, extracting message flow from a spec or RFC, diagramming a ProVerif or Tamarin model, or drawing sequence diagrams for TLS, Noise, Signal, X3DH, Double Ratchet, FROST, DH, or ECDH protocols.

Install

With the skills CLI, which installs into Claude Code, Codex, Cursor and other agents:

npx skills add trailofbits/skills --skill crypto-protocol-diagram

Or copy the skill folder into Claude Code's skills directory by hand (~/.claude/skills for every project, or .claude/skills inside one):

git clone --depth 1 https://github.com/trailofbits/skills
cp -r skills/plugins/trailmark/skills/crypto-protocol-diagram ~/.claude/skills/crypto-protocol-diagram

Safety box score

Not rated yet. A safety box score grades what a skill and its scripts can reach on the machine of whoever installs it, across eight categories from shell execution to secrets access. Anyone can request one from this page; it is saved for everyone. How the score works.

Source

Repository

trailofbits/skills (all skills from this repository)

Path

plugins/trailmark/skills/crypto-protocol-diagram/SKILL.md

Branch

main

Collection

trailmark

Updated

2026-09-19

Related skills

• diagramming-code — Generates Mermaid diagrams from Trailmark code graphs.
• mermaid-to-proverif — pv files). pv file from a sequence diagram.
• trailmark-summary — Runs a Trailmark summary analysis on a codebase. Returns auto-detected languages, entry point count, and dependency list.
• vector-forge — Mutation-driven test vector generation.
• audit-prep-assistant — Prepares codebases for security review using Trail of Bits' checklist.
• constant-time-analysis — Detects timing side-channel vulnerabilities in cryptographic code.