Keystone supports four different types of tokens, UUID, PKI, PKIZ, and Fernet. Let’s take a deep dive into: Understanding token formats Pros and Cons of each format in Production Performance across multiple data centers Token revocation workflow for each of the formats Horizon usage of the different token types We previously deployed UUID and PKI in Production and are now moving towards the latest format, Fernet. We would like to share our lessons learned with different formats and help you decide on which format is suitable for your cloud.