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

# Introduction

> Learn about SHIELD - decentralized, end-to-end encrypted file sharing for web3

# What is SHIELD?

SHIELD is a decentralized application (dApp) that enables secure sharing of confidential content—files and messages—with anyone who owns a web3 wallet. Built on the principles of trustless security, SHIELD ensures your content is only ever decrypted by your intended recipient.

## Key Features

<CardGroup cols={2}>
  <Card title="End-to-End Encryption" icon="lock">
    Content is encrypted in your browser using AES-GCM 256 before leaving your device
  </Card>

  <Card title="Web3 Native" icon="wallet">
    No passwords or email required. Authenticate with your Ethereum wallet via SIWE
  </Card>

  <Card title="On-Chain Access Control" icon="shield">
    Smart contracts enforce who can access content, when, and how many times
  </Card>

  <Card title="Decentralized Storage" icon="cloud">
    Encrypted content stored on IPFS for censorship-resistant, content-addressed storage
  </Card>
</CardGroup>

## How It Works

<Steps>
  <Step title="Encrypt">
    Upload a file or write a message. SHIELD encrypts it locally using AES-GCM 256.
  </Step>

  <Step title="Store">
    Encrypted content is uploaded to IPFS. Only the encrypted data leaves your device.
  </Step>

  <Step title="Set Policy">
    Define who can access it (by wallet address), when it expires, and max attempts.
  </Step>

  <Step title="Share">
    Send the secure link to your recipient. The decryption key is in the URL fragment.
  </Step>

  <Step title="Access">
    Recipient proves wallet ownership, signs on-chain transaction, and decrypts locally.
  </Step>
</Steps>

## Why SHIELD?

Traditional file sharing services require you to trust the provider with your data. SHIELD changes this by:

* **Never** storing your encryption keys on any server
* **Never** having access to unencrypted content
* **Enforcing** access control via immutable smart contracts
* **Creating** an on-chain audit trail of every access attempt

## Quick Links

<CardGroup cols={3}>
  <Card title="Quick Start" icon="rocket" href="/getting-started/quickstart">
    Get up and running in 5 minutes
  </Card>

  <Card title="User Guide" icon="book" href="/user-guide/creating-secure-links">
    Learn how to use SHIELD
  </Card>

  <Card title="Developer Docs" icon="code" href="/developers/local-setup">
    Build on top of SHIELD
  </Card>
</CardGroup>