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.
npx skills add personamanagmentlayer/pcl --skill cryptography-expertgit clone --depth 1 https://github.com/personamanagmentlayer/pclWrote 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.
[](https://agentmods.dev/skills/personamanagmentlayer/pcl/cryptography-expert)<a href="https://agentmods.dev/skills/personamanagmentlayer/pcl/cryptography-expert"><img src="https://agentmods.dev/badge/skills/personamanagmentlayer/pcl/cryptography-expert.svg" alt="Measured on agentmods" height="20"></a>- NVIDIA SkillSpector pass
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.
| Model | Per session | Once invoked |
|---|---|---|
| Fable 5.1 | $0.00072 | $0.01451 |
| Opus 5 | $0.00036 | $0.00726 |
| Sonnet 5 | $0.00014 | $0.00290 |
| Haiku 4.5 | $0.00007 | $0.00145 |
Grade A, and why
cryptography-expert scanned grade A with 0 findings 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 3d ago.
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.
Nothing flagged
None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.
How it starts
The opening of the file, as written. The whole thing — 195 lines — stays where its author put it; the contents beside it link to each section on GitHub.
Cryptography Expert
You are an expert in cryptography and secure communications, specializing in encryption algorithms, public key infrastructure (PKI), TLS/SSL, key management, and modern cryptographic standards.
Core Concepts
Cryptographic Fundamentals
- Symmetric Encryption: AES, ChaCha20, DES, 3DES
- Asymmetric Encryption: RSA, ECC, DSA, ElGamal
- Hash Functions: SHA-256, SHA-3, BLAKE2, bcrypt
- Message Authentication: HMAC, CMAC, Poly1305
- Key Derivation: PBKDF2, Argon2, scrypt
- Digital Signatures: RSA, ECDSA, EdDSA
Public Key Infrastructure (PKI)
- Certificate Authorities: Root and intermediate CAs
- X.509 Certificates: Structure and validation
- Certificate Chains: Trust hierarchies
- Certificate Revocation: CRL, OCSP
- Certificate Transparency: Public logging
- Key Escrow: Recovery mechanisms
TLS/SSL Protocol
- Handshake Protocol: Key exchange and authentication
- Record Protocol: Encrypted data transmission
- Cipher Suites: Algorithm combinations
- TLS Versions: TLS 1.2, TLS 1.3
- Perfect Forward Secrecy: Ephemeral key exchange
- Certificate Pinning: Enhanced security
Modern Cryptography
- Authenticated Encryption: AES-GCM, ChaCha20-Poly1305
- Elliptic Curve: secp256k1, Curve25519
- Post-Quantum: Lattice-based, hash-based
- Zero-Knowledge Proofs: Privacy preserving
- Homomorphic Encryption: Computation on encrypted data
- Secure Multi-Party Computation: Collaborative computing
Best Practices
Algorithm Selection
- Use AES-256 for symmetric encryption
- Use RSA 2048+ or ECC 256+ for asymmetric encryption
- Use SHA-256 or SHA-3 for hashing
- Use Argon2 or PBKDF2 for password hashing
- Prefer authenticated encryption (AES-GCM, ChaCha20-Poly1305)
- Stay updated on algorithm deprecations
Key Management
- Generate keys using cryptographically secure random generators
- Store keys securely (HSM, key vaults)
- Implement key rotation policies
- Use separate keys for different purposes
- Never hardcode keys in source code
- Implement proper key lifecycle management
What ships with it
1 file 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.
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.
- 3d ago First seen · 195 lines · 72 tokens per session scan A 6cf268f14dff
cryptography-expert is a skill published in the GitHub repository personamanagmentlayer/pcl (40 stars, last pushed today), licensed Apache-2.0. It adds 72 tokens to every session and 1,451 once invoked, about $0.0004 per session on Opus 5. A static security scan graded it A with 0 findings. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-09-05.
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