A method for access control to installation control systems of wind energy installations. The method includes receiving a requested user name and a requested password, wherein authorizations and checking information are coded in the requested password. The method further includes decoding the authorizations and the checking information from the requested password, checking the requested user name on the basis of the decoded checking information, checking the decoded authorizations if the check of the requested user name on the basis of the decoded checking information has a positive result, and allowing access to an installation control system of a wind energy installation when the decoded authorizations are sufficient. A wind energy installation for implementing the method includes an installation control system and a decoding unit.