Transmitter, a receiver and methods. therein for validation of a video sequence

A method performed by a receiver for validating a video sequence provided with a data structure and a digital signature, wherein the video sequence comprises encoded image frames, the method comprising:

• receiving, from a transmitter, the video sequence comprising encoded image frames and being provided with the data structure and the digital signature,
• wherein the received data structure comprises:
• one or more small losslessly compressed (LC) encoded image frames, each small LC encoded image frame has a data size that is smaller than a predefined number of bytes and is an LC version of a respective transmitted encoded image frame comprised in a video sequence transmitted from the transmitter;
• and
• individual hashes of either:
• all transmitted encoded image frames lacking a respective small LC encoded image frame;
• or
• all other LC encoded image frames being different from the one or more small LC encoded image frames, wherein each one of the all other LC encoded image frames is an LC version of a respective transmitted encoded image frame comprised in the transmitted video sequence;
• verifying the received digital signature using the received data structure;
• and
• verifying the received encoded image frames as being equal to the transmitted encoded image frames using the received data structure;
• whereby the received video sequence is validated as being equal to the transmitted video sequence when the received digital signature and the received encoded image frames are verified.

A transmitter for enabling validation of a video sequence by providing the video sequence with a data structure and a digital signature, wherein the transmitter comprises processing circuitry configured to cause the transmitter to:

• perform lossless compression of each encoded image frame of the video sequence to obtain a respective losslessly compressed (LC) encoded image frame;
• identify one or more LC encoded image frames, each having a data size that is smaller than a predefined number of bytes, as small LC encoded image frames;
• generate a data structure comprising:
• the one or more small LC encoded image frames;
• and
• individual hashes of either:
• all encoded image frames lacking a respective small LC encoded image frame;
• or
• all other obtained LC encoded image frames being different from the one or more small LC encoded image frames,
• wherein the individual hashes are obtained by individually hashing each one of the all encoded image frames lacking a respective small LC encoded image frame, or by individually hashing each one of the all other obtained LC encoded image frame, respectively;
• generate a digital signature for the video sequence;
• and
• provide the data structure and the digital signature to the video sequence, thereby enabling a receiver to validate the video sequence.

A receiver for validating a video sequence provided with a data structure and a digital signature, wherein the receiver comprises processing circuitry configured to cause the receiver to:

• receive the video sequence comprising encoded image frames and being provided with the data structure and the digital signature,
• wherein the received data structure comprises:
• one or more small losslessly compressed (LC) encoded image frames, each small LC encoded image frame has a data size that is smaller than a predefined number of bytes and is an LC version of a respective transmitted encoded image frame comprised in a video sequence transmitted from the transmitter;
• and
• individual hashes of either:
• all transmitted encoded image frames lacking a respective small LC encoded image frame;
• or
• all other LC encoded image frames being different from the one or more small LC encoded image frames, wherein each one of the all other LC encoded image frames is an LC version of a respective transmitted encoded image frame comprised in the transmitted video sequence;
• verifying the received digital signature using the received data structure;
• and
• verifying the received encoded image frames as being equal to the transmitted encoded image frames using the received data structure;
• whereby the received video sequence is validated as being equal to the transmitted video sequence when the received digital signature and the received encoded image frames are verified.