Multi-factor authentication for virtual reality

1. A method of authenticating for a virtual reality (VR) system using a plurality of factors of authentication, the method comprising:

collecting a password entered into a virtual keyboard for a first factor of the plurality of factors of authentication,

wherein the password is entered by a user gazing at and selecting a series of data including numbers, letters, or images on the virtual keyboard randomly projected in polar coordinates on a display of the VR system such that each data of the series of data projected on the display is represented by an azimuth angle and an elevation angle;

collecting a biometric fingerprint from movements of the VR system for a second factor of the plurality of factors of authentication,

wherein the biometric fingerprint is collected from detecting head gestures of the user including at least one of head movements and eye gazes using the VR system,

wherein a pre-defined acknowledging head gesture and a pre-defined unselecting head gesture are detected using a combination of phases including: a first pause in which the VR system is still; a movement of the VR system in a first direction; a movement of the VR system in a second direction opposite to the first direction; and a second pause in which the VR system is still;

wherein the biometric fingerprint is measured as acceleration projected on two axes of the polar coordinates,

wherein the projected acceleration is generated by:

measuring a first measured acceleration of the pre-defined acknowledging head gesture; measuring a second measured acceleration of the pre-defined unselecting head gesture; and normalizing the first and second measured accelerations.

2. The method of claim 1 , wherein the VR system is a head-mounted display (HMD).

3. The method of claim 1 , further comprising

displaying the virtual keyboard on a half sphere in a fixed position within the half sphere.

4. The method of claim 3 , wherein the virtual keyboard is arranged as a random display of at least ten keys on the half sphere.

5. The method of claim 1 , wherein the password is entered by gazing in a direction of a button on the virtual keyboard to select the button.

6. The method of claim 5 , wherein the selected button is validated by making the pre-defined acknowledging head gesture.

7. The method of claim 6 , wherein selection of the selected button is removed by making the pre-defined unselecting head gesture.

8. The method of claim 7 , wherein the biometric fingerprint is collected from the movements of the VR system as reflected in the pre-defined acknowledging head gesture and the pre-defined unselecting head gesture.

9. The method of claim 1 , further comprising:

comparing the collected biometric fingerprint to fingerprints in a fingerprint database; and

identifying the user when a fingerprint match is made.

10. The method of claim 9 , wherein the fingerprint match means that a similarity of the collected biometric fingerprint and a reference fingerprint of the fingerprint match are within a defined boundary.