Authentication is the process of identifying the current user. TiddlyWiki supports three types of authentication:

• Anonymous Access allows any user to access resources without requiring authentication. Optionally, a username can still be specified for signing edits
• Basic Authentication requires the user to enter a username and password combination which TiddlyWiki validates against an internal database of credentials
• Header Authentication requires an external proxy to place the username of the current user in a trusted header of the request. It is often used as the basis of "single sign-on" features