Abstract: A user verification system responding to voice commands comprises a control unit (11, 21), input means (221) for receiving voice commands and output means (224, 225) for presenting information to the user. The control unit (21) is adapted to create a hash value from one or more received voice commands which is presented to the user by use of the output means (224, 225). The input means (221) is adapted to receive the hash value from the user in form of a spoken message, and the control unit is further adapted to verify the identity of the user based on the received hash value.