Cryptographic Analysis & Assessment

Cryptographic Analysis & Assessment is a skill for Claude Code from Masriyan/Claude-Code-CyberSecurity-Skill. It costs 30 tokens per session (4,090 once invoked), scanned A, original, MIT.

A security review assistant for encryption and secure communications. It checks SSL/TLS settings, cipher suites, hashes, certificates, keys, and cryptographic code for weaknesses.

In plain words
What is it for?
Use it to review TLS configurations, cipher strength, hash algorithms, certificates, key lengths and rotation, hardcoded keys, weak IVs, ECB mode, and password hashing with bcrypt, Argon2, or PBKDF2.
Why use it?
Cryptography is easy to implement incorrectly even when the code appears to work. This add-on helps identify weak algorithms, unsafe settings, exposed keys, and problems in password-hashing or key-management code.

Skill for Claude Code

Written for Claude Code: shipped in a Claude Code plugin. Also seen: positional $N argument.

Part of the cybersecurity plugin — 20 skills shipped together

Good fit Use it to review TLS configurations, cipher strength, hash algorithms, certificates, key lengths and rotation, hardcoded keys, weak IVs, ECB mode, and password hashing with bcrypt, Argon2, or PBKDF2.

Compare 6 skills from other repositories ↓
Install with agentmods
npx agentmods add skills/masriyan/claude-code-cybersecurity-skill/13-crypto-analysis
Install

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.

Any agent
npx skills add Masriyan/Claude-Code-CyberSecurity-Skill --skill 13-crypto-analysis
Clone the repo
git clone --depth 1 https://github.com/Masriyan/Claude-Code-CyberSecurity-Skill

Made for: Claude Code.

Or install cybersecurity, the plugin that ships this one along with the rest of its 20 skills.

Wrote 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.

agentmods badge for Cryptographic Analysis & Assessment

README.md
[![agentmods](https://agentmods.dev/badge/skills/masriyan/claude-code-cybersecurity-skill/13-crypto-analysis.svg)](https://agentmods.dev/skills/masriyan/claude-code-cybersecurity-skill/13-crypto-analysis)
Your own site
<a href="https://agentmods.dev/skills/masriyan/claude-code-cybersecurity-skill/13-crypto-analysis"><img src="https://agentmods.dev/badge/skills/masriyan/claude-code-cybersecurity-skill/13-crypto-analysis.svg" alt="Measured on agentmods" height="20"></a>
Per session 30 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 4,090 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 1 finding. A grade says what 26 rules found in the file — not that it is safe. Third-party audits
  • NVIDIA SkillSpector warn 7 Sept 2026
SkillSpector: 1 finding, up to medium

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 →

  • medium Tool Misuse · line 229
    Tool defaults are unsafe or overly permissive (e.g. disabled TLS verification, no authentication, world-writable permissions). Unsafe defaults widen the attack surface.
    Fix: Override unsafe defaults with secure settings (verify=True, auth required, restrictive permissions). Review and harden all tool configurations.
How audits are shown
Origin original No closer match found in the catalogue.
Token cost

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.

ModelPer sessionOnce invoked
Fable 5.1 $0.00030 $0.04090
Opus 5 $0.00015 $0.02045
Sonnet 5 $0.00006 $0.00818
Haiku 4.5 $0.00003 $0.00409

Measured 8d ago against content hash 6bffb708e2ed, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-07, from the pricing page.

Security

Grade A, and why

Cryptographic Analysis & Assessment scanned grade A with 1 finding 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 8d ago.

The scan reads SKILL.md. This mod also ships 1 executable file (scripts/tls_auditor.py), listed below but not scanned — reading those needs a real analyzer, not pattern matching.

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.

Makes network callslowCapability

Not a fault in itself. Listed so you know the mod talks to something, and to what.

requests.get(url, verify=False) # ← Never do this in production
skills/13-crypto-analysis/SKILL.md · 372 lines

How it starts

The opening of the file, as written. The whole thing — 372 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Cryptographic Analysis & Assessment

Purpose

Enable Claude to assist with cryptographic security assessments including SSL/TLS configuration auditing, cipher suite analysis and recommendation, hash algorithm identification, encryption implementation code review, key management evaluation, and detection of cryptographic vulnerabilities. Claude directly analyzes provided configurations and code.


Activation Triggers

This skill activates when the user asks about:

  • Auditing SSL/TLS configuration of a server or service
  • Evaluating cipher suites for security strength
  • Identifying hash algorithms from hash values or code
  • Reviewing code for cryptographic implementation flaws
  • Assessing key lengths, key management, or rotation policies
  • Detecting hardcoded keys, weak IVs, or ECB mode usage
  • Generating TLS configuration recommendations (Mozilla profile)
  • Certificate analysis (expiration, chain, transparency)
  • Post-quantum cryptography guidance
  • Password hashing implementation review (bcrypt, Argon2, PBKDF2)

Prerequisites

pip install cryptography requests pyOpenSSL

Recommended tools:

  • sslyze — Python TLS scanner
  • testssl.sh — Comprehensive TLS testing
  • openssl — Command-line TLS operations
  • Wireshark — TLS traffic analysis
  • certbot — Certificate management

Core Capabilities

1. SSL/TLS Configuration Auditing

When the user asks to audit TLS for a server or paste a TLS configuration:

Command-line audit approach:

# Quick TLS check using openssl
openssl s_client -connect example.com:443 -tls1_2 2>/dev/null | grep -E "Protocol|Cipher"
openssl s_client -connect example.com:443 -tls1 2>/dev/null | grep -E "handshake|error"

# Check certificate details
openssl s_client -connect example.com:443 </dev/null 2>/dev/null | openssl x509 -noout -dates -subject -issuer

# Comprehensive scan with sslyze
sslyze --regular example.com --json_out result.json

# Or testssl.sh (most comprehensive)
./testssl.sh --severity HIGH --quiet example.com

# Use the skill's script
python scripts/tls_auditor.py --host example.com --port 443 --output report.json
python scripts/tls_auditor.py --host mail.example.com --port 993 --grade

Read the full file on GitHub · 372 lines

Files

What ships with it

3 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.

Changes

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.

  1. 8d ago First seen · 372 lines · 30 tokens per session scan A 6bffb708e2ed

Subscribe to this mod's changes

Cryptographic Analysis & Assessment is a skill published in the GitHub repository Masriyan/Claude-Code-CyberSecurity-Skill (399 stars, last pushed 4d ago), licensed MIT. It adds 30 tokens to every session and 4,090 once invoked, about $0.0002 per session on Opus 5. A static security scan graded it A with 1 finding (makes network calls). No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-30.

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