A user device comprising a processor configured to enable a mnemonic based digital signature scheme for user authentication that is based on a combination of one or more secrets and one or more actions implemented on the user device and associated with the secrets, and a device input system coupled to the processor and configured to detect the actions implemented on the user device. Also disclosed is an apparatus comprising a processor configured to implement a mnemonic based digital signature for authenticating a user, a device input system configured to enable the mnemonic based digital signature, and a memory unit configured to store input data that is used to recognize the mnemonic based digital signature, wherein the mnemonic based digital signature comprises a secret, an action associated with the secret and implemented using the device input system, and a cue associated with the action.