1. A method of responding to a query at a dialog system, the method comprising: by the dialog system, returning a response to the query by an interaction device, the response identifying the dialog system as a signed dialog system in an event the response includes a representation of an embedded steganographic signature, otherwise the response identifying the dialog system as an unsigned dialog system or a dialog system without the embedded steganographic signature.
1. A method of responding to a query at a dialog system, the method comprising: by the dialog system, returning a response to the query by an interaction device, the response identifying the dialog system as a signed dialog system in an event the response includes a representation of an embedded steganographic signature, otherwise the response identifying the dialog system as an unsigned dialog system or a dialog system without the embedded steganographic signature. 2. The method of claim 1 , further comprising, by the dialog system, returning the response encrypted with a key to enable decrypting the response at the interaction device.