```markdown:docs/use-cases/secure-messaging.md

Secure Messaging¶

Self provides a secure messaging framework that allows users to communicate with each other using their digital identities. This framework is designed to ensure privacy and security, making it suitable for various applications, such as:

• Encrypted messaging for web applications
• Encrypted messaging for mobile applications
• Encrypted messaging for desktop applications

How to Build a Secure Messaging Workflow¶

You can build a simple secure messaging workflow with Self using just a few key features. Let's break down the process into steps:

1. Setting Up the Self Account¶

First, we need to initialize a Self account. This account will be used to interact with the Self network and other entities. For detailed information on setting up your account, refer to the Setup Guide.

Here's a snippet from the main.go file that initializes the Self account:

```go:examples/messaging/main.go func initializeSelfAccount() (*SelfAccount, error) { account, err := NewSelfAccount("user@example.com", "securepassword") if err != nil { return nil, err } return account, nil }

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### 2. Self Discovery

To establish a secure messaging channel, we first need to discover the DIDs (Decentralized Identifiers) of the users we want to communicate with. We use Self Discovery for this purpose. For more information on the discovery process, see the [Discovery Guide](../essentials/discovery.md).

The `discoverDIDs` function in `discovery.go` handles this process:

```go:examples/messaging/discovery.go
func discoverDIDs(userID string) ([]string, error) {
    // Implementation for discovering DIDs
    return []string{"did:self:12345"}, nil
}

3. Sending Encrypted Messages¶

Once the DIDs are discovered, we can send encrypted messages using Self's messaging capabilities. This ensures that communications are secure and private.

Refer to the sendMessage method in messaging.go:

```go:examples/messaging/messaging.go func (m *Messenger) sendMessage(recipientDID, message string) error { encryptedMsg, err := EncryptMessage(recipientDID, message) if err != nil { return err } // Code to send the encrypted message return nil }

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### 4. Handling Incoming Messages

To maintain a secure communication channel, it's essential to handle incoming messages appropriately. This involves decoding messages, validating their integrity, and responding as needed.

The `handleIncomingMessage` function in `handler.go` manages incoming messages:

```go:examples/messaging/handler.go
func handleIncomingMessage(encryptedMsg string) error {
    message, err := DecryptMessage(encryptedMsg)
    if err != nil {
        return err
    }
    // Validate and process the message
    return nil
}

Conclusion¶

This example demonstrates how to build a simple secure messaging workflow with Self. We've seen how to:

1. Set Up the Self Account: Initialize and configure your Self account for secure interactions.
2. Self Discovery: Discover the DIDs of the users you want to communicate with using QR codes.
3. Send Encrypted Messages: Utilize Self's messaging capabilities to send and receive encrypted messages.
4. Handle Incoming Messages: Properly handle and validate incoming messages to maintain a secure communication channel.

For the complete example, including error handling and additional details, please refer to our GitHub repository.

By leveraging these Self features, you can create a robust, secure, and privacy-preserving messaging system for your applications. ```