Decentralized Operation, Centralized Management
One of the core requirements in Userify’s architectural design was fully decentralized operation.
Userify's fully decentralized operation means that, in essence, your servers do not rely on an external service for authentication, so you can always log in.
Unlike connecting your servers to external authentication services (such as Active Directory, LDAP, etc), Userify creates local instances of your user's SSH public keys.
Public keys are literally public; they are not secret material. The private keys stay safely on your user's laptop or desktop, where they can be revoked remotely using Userify. A user can have as many private and public keys as they like. (We recommend at least one per device, so that if that device is lost or stolen, that device key can be revoked.)
Even though Userify's operation is decentralized, the servers stay in sync with the centralized Userify management portal (aka controllers) to ensure continuously monitored operation and centralized management. Each server registers with Userify upon initial connection and is tracked throughout its lifecycle.
Read More about How Userify Works.