"Speak, Friend, and Enter" - Secure, Spoken One-Time Password Authentication

User authentication is a long-standing problem in need of a comprehensive solution. As technology progresses towards more ubiquitous connectivity and digital services, there is a need for new methods that are usable in these new contexts. One direction of progress has been in virtual and augmented reality technologies. Augmented reality provides tools also for better user authentication. We have developed a system, where user authentication can be done with the help of augmented reality, visual cryptography and speech recognition. This type of authentication can be used in untrusted environments and in scenarios, where the hands of the user are not available for inputting a password with some keyboard.