It is called Single Sign On (SSO). You should choose and setup an SSO server first, integrate it with your PHP application and then use an SSO plugin for Jira to integrate Jira to SSO.
For example, you can use the Kantega plugin:
Or find any other SSO plugins in the Atlassian Marketplace
You must be a registered user to add a comment. If you've already registered, sign in. Otherwise, register and sign in.