A method and system for authenticating a credential via a one time password which includes receiving a user ID, a client ID, and the one time password from a client device, and then validating the one time password based on the user ID and the credential ID. Upon validating the one time password, a response is sent to the client device, and the response includes at least one of an authorization to access a private key stored on the client device or at least a portion of the private key.