# Specification Change Log
source: https://developer.mastercard.com/authentication-facilitator/documentation/api-reference/spec-change-log/index.md

Occasionally the Authentication Facilitator API specification requires an update for clarification of existing functionality and can occur at any time. No backwards breaking changes will be introduced, and the requests and responses returned from the service will not change without prior notice.

|                                                        Version                                                         |                                                                                  Description                                                                                  |  Release Info  |   |
|------------------------------------------------------------------------------------------------------------------------|-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|----------------|---|
| [1.1.0](https://static.developer.mastercard.com/content/authentication-facilitator/documentation/api-reference/1.1.0/) | Enhanced the Deliver Authentication Code API by adding new fields and updating existing parameter to support AES Galois/Counter Mode (GCM) cipher mode for enhanced security. | March 2026     |   |
| [1.0.3](https://static.developer.mastercard.com/content/authentication-facilitator/documentation/api-reference/1.0.3/) | Documentation improvements for better readability.                                                                                                                            | November 2022  |   |
| [1.0.2](https://static.developer.mastercard.com/content/authentication-facilitator/documentation/api-reference/1.0.2/) | Documentation improvements for better readability.                                                                                                                            | September 2022 |   |
| [1.0.1](https://static.developer.mastercard.com/content/authentication-facilitator/documentation/api-reference/1.0.1/) | Added new optional parameters to the Token Requestor object in the Deliver Authentication Code API.                                                                           | June 2021      |   |