This document discusses 3-D passwords as a multifactor authentication method. 3-D passwords involve navigating and interacting with objects in a virtual 3-D environment, with the sequence of actions constructing the unique password. The 3-D environment could include various real-world objects. Designing the virtual world affects usability and security, with guidelines including real-life similarity of objects, uniqueness, size, number of objects, and importance of the system being protected. Potential applications mentioned include servers, military facilities, airplanes, as well as smaller-scale uses like ATMs, laptops, and websites.