# Visa Alias Directory Service

## Simplify the push payment experience. Link and resolve an Alias to a payment credential.

[Start a Project](https://developer.visa.com/portal/#users/new)    [API Overview](https://developer.visa.com/capabilities/alias-directory-service)    [API Reference](https://developer.visa.com/capabilities/alias-directory-service/reference)

- [Getting Started with Visa Alias Directory Service](https://developer.visa.com/capabilities/alias-directory-service/docs-getting-started)
- [Use Cases and Implementation Examples](https://developer.visa.com/capabilities/alias-directory-service/alias-directory-use-cases)
- [Authentication and Encryption](https://developer.visa.com/capabilities/alias-directory-service/docs-authentication)
  - [Security and Authentication Requirements](https://developer.visa.com/capabilities/alias-directory-service/docs-authentication#section0)
  - [Data Encryption](https://developer.visa.com/capabilities/alias-directory-service/docs-authentication#section1)
- [How to Use Visa Alias Directory Service](https://developer.visa.com/capabilities/alias-directory-service/docs-how-to)
- [How to Use Directory Network Manager](https://developer.visa.com/capabilities/alias-directory-service/docs-how-to-use-dnm)
- [How to Use Batch Processing](https://developer.visa.com/capabilities/alias-directory-service/docs-how-to-use-batch)
- [Error Codes](https://developer.visa.com/capabilities/alias-directory-service/docs-error-codes)
- [API Reference](https://developer.visa.com/capabilities/alias-directory-service/reference)
- [Product Terms](https://developer.visa.com/capabilities/alias-directory-service/ProductTerms)

## Visa Alias Directory Service Authentication and Encryption

### Security and Authentication Requirements

All of the Visa Alias Directory Service APIs requires Two-Way SSL (Mutual Authentication) or X-Pay Token for authentication.

#### Two-Way SSL

As one of the security protocols, Visa Developer secures its connections with clients by means of Two-Way SSL (Mutual Authentication) method.

Please refer to the [Two-Way SSL tutorial](https://developer.visa.com/pages/working-with-visa-apis/two-way-ssl) to quickly learn about how to get credentials to start building with Two-Way SSL.

**Note for clients connecting to api.uk.visa.com:**

Clients connecting to api.uk.visa.com may need to install additional certificates. Please speak with your implementation manager and [visit this page](https://developer.visa.com/pages/visa-developer-pki) for more information.

#### X-Pay Token

Some Visa Developer APIs require an API Key-Shared Secret Authentication, which Visa refers to as x-pay-token. To invoke an API using x-pay-token, you will need an API Key and a Shared Secret, which is provided via the link below.

Visit the [X-pay Token Guide](https://developer.visa.com/pages/working-with-visa-apis/x-pay-token) to learn more.

### Data Encryption

#### Message Level Encryption

Visa requires Message Level Encryption (MLE) for Visa Alias Directory Service APIs.

Please refer to the [Message Level Encryption](https://developer.visa.com/pages/encryption_guide) guide for more details.

Please refer to this [tutorial](https://community.developer.visa.com/t5/Message-Level-Encryption/How-to-test-MLE-on-Postman/td-p/17286) and Postman collection to quickly enable Message Level Encryption for our APIs.