> ## Documentation Index
> Fetch the complete documentation index at: https://docs.hasmcp.com/llms.txt
> Use this file to discover all available pages before exploring further.

# What is AES-256-GCM encryption, and why does HasMCP use it?

> Reviewing the military-grade standard chosen for internal secret vaults.

# AES-256-GCM Encryption

HasMCP exclusively utilizes **AES-256-GCM** to secure all internal Environment Variables, Server Tokens, and Provider Authentication strings.

### What is AES-256?

AES (Advanced Encryption Standard) with a 256-bit key length is the premier cryptographic standard globally. It is the exact same encryption implementation required by the NSA for handling "Top Secret" government intelligence.

A 256-bit key means there are $2^{256}$ possible combinations. With current classical computing infrastructure, it would take billions of years to brute force a single secret variable stored within the HasMCP database.

### Why GCM?

GCM stands for **Galois/Counter Mode**.

While standard AES encryption prevents someone from *reading* your secret, it does not necessarily prevent them from *tampering* with it. GCM solves this by explicitly incorporating authentication into the encryption pass natively.

Whenever HasMCP encrypts your API key, GCM simultaneously generates a cryptographic tag. During decryption, the proxy server verifies this tag. If the encrypted string was altered by even a single bit in the database, the tag fails validation, and the system securely permanently drops the request instead of transmitting a corrupted payload.