The **Key Verifier SDK** works in conjunction with the
[**Android System Key Verifier**](https://developer.android.com/privacy-and-security/key-verifier/key-verifier), a Google system service available on
Android devices.

This service aims to improve **user privacy** in end-to-end encrypted (E2EE)
messaging applications. Key Verifier provides a unified system for public key
verification across different client apps.

The fundamental goal of Key Verifier is to enable **private communication**
through encryption by validating that you are communicating with the person you
expect.

The following are main functions of the system:

- **Key Verification**: Allows a user to verify a contact's public keys to confirm they are communicating with the person they intend to message.
- **Verification Methods** : Users can verify keys through a user interface that supports **QR code scanning or number comparison** (matching a sequence of numbers).
- **Key Management** : Exposes a service through an **AIDL interface** for client applications to insert, read, update, or delete keys.
- **Client SDK**: Provided to all apps, such as messaging or contacts management apps, to interact with the service.

Learn more about Key Verifier in the following documentation:

- [Android System Key Verifier](https://developer.android.com/privacy-and-security/key-verifier/key-verifier)
- [Key Verifier reference documentation](https://developer.android.com/privacy-and-security/key-verifier/reference)