This document discusses 3D passwords as an authentication method. It begins by describing traditional authentication methods like knowledge-based, token-based, and biometric authentication. It then introduces the concept of 3D passwords, which combine recognition, recall, tokens, and biometrics within a 3D virtual environment. The document outlines the advantages of 3D passwords and potential applications. It also discusses threats like brute force, shoulder surfing, and timing attacks along with countermeasures. In conclusion, the document argues that 3D passwords can improve authentication by making passwords difficult to crack.