A system and method for providing authenticating user access to an access controlled device such as computers, mobile devices, or tablets. The present disclosures describes a novel method and system for eye tracking performed through the execution of computer software on a nontransitory computer-readable medium to measure neurological impulses through physiological expressions of the user. These measurements are unique to each user and therefore ideal for the use in the field of encryption and decryption. This novel system can potentially make mobile devices significantly more secure. Preferably, the system comprises a user interface and a camera.