Concept for trustworthiness check of video data streams

Patent metadata

Field	Value
Publication number	US-12489925-B2
Application number	US-202519097518-A
Country	US
Kind code	B2
Filing date	Apr 1, 2025
Priority date	Apr 2, 2024
Publication date	Dec 2, 2025
Grant date	Dec 2, 2025

Abstract

A method for checking a video data stream having a video encoded thereinto on trustworthiness comprises: subjecting a predetermined portion of the video data stream, or data derived therefrom, to a hash function to obtain a hash value; deriving a digital signature from the video data stream; and checking whether the hash value fits to the digital signature to determine whether the video data stream is trustworthy.

First claim

The invention claimed is:

1 . Apparatus for checking a video data stream having a video encoded thereinto on trustworthiness, wherein the apparatus is configured for
subjecting a predetermined portion of the video data stream, or data derived therefrom, to a hash function to acquire a hash value; deriving a digital signature from the video data stream; and checking whether the hash value fits to the digital signature to determine whether the video data stream is trustworthy, wherein the video data stream has the video encoded thereinto by encoding the video into the video data stream by block based predictive coding and transform based residual coding by encoding the prediction residual data of the residual block into the video data stream by use of context adaptive variable length coding by using
a first syntax element indicating a total number of non-zero transform coefficients in a transform block representing the residual block, and a trailing-one number, indicating a number of non-zero transform coefficients comprising an absolute value of one when traversing the coefficients along a scan order,
one or more second syntax elements indicating a sign of the non-zero transform coefficients comprising an absolute value of one when traversing the coefficients along the scan order,
one or more third syntax elements indicating a value of the non-zero transform coefficients except for the number of non-zero transform coefficients comprising an absolute value of one when traversing the coefficients along the scan order,
a fourth syntax element indicating a total number of zero-valued transform coefficient levels in the transform block from a firstly-encountered non-zero transform coefficient in the scan order onwards, and
one or more fifth syntax elements indicting positions of the non-zero transform coefficients along the scan order by indicating a number of consecutive zero-valued transform coefficients in the scan order between in the scan order consecutively encountered non-zero transform coefficients.

2 . Apparatus according to claim 1 , wherein the digital signature is transmitted in an supplemental enhancement information message of the video data stream.

3 . Apparatus according to claim 1 , configured for, in checking whether the hash value fits to the digital signature to determine whether the video data stream is trustworthy,
decrypting the digital signature to acquire a check value; and checking whether the hash value matches the check value.

4 . Apparatus according to claim 1 , the apparatus being a decoder configured for
decoding the video from the video data stream, and decoding the digital signature from the video data stream.

5 . Apparatus according to claim 1 , configured for locating the predetermined portion within the video data stream by use of one or more SEI messages interspersed into video data stream and determining the predetermined portion to be a section of the video data stream extending between, or extending from, the one or more SEI messages.

6 . Apparatus according to claim 1 , configured for locating the predetermined portion within the video data stream by use of a first SEI message and a second SEI message interspersed into video data stream and determining the predetermined portion to be located between the first and the second SEI messages, or located between the first SEI message and a point in the data stream which is located downstream the second SEI message.

7 . Apparatus according to claim 1 , configured for
deriving an overview SEI message from the video data stream, the overview SEI message indicating one or more substreams of the video data stream with respect to each of which the checking the video data stream on trustworthiness is possible based on one or more portions in the respective substream; and performing the checking the video data stream on trustworthiness with respect to a subset of one or more substreams of the one or more substreams by, for a predetermined substream out of the subset,
locating a portion of the predetermined substream of the video data stream by use of one or more first SEI messages interspersed into video data stream and determining the portion of the predetermined substream to be a section of the video data stream formed by concatenating subsections of the video data stream following each of the one or more first SEI messages and extending up to a video coding layer end of an access unit the respective first SEI message is comprised in.

8 . Apparatus according to claim 1 , configured for
deriving an overview SEI message from the video data stream, the overview SEI message indicating one or more substreams of the video data stream with respect to each of which the checking the video data stream on trustworthiness is possible based on one or more portions in the respective substream; and performing the checking the video data stream on trustworthiness with respect to a subset of one or more substreams of the one or more substreams by determining respective portions of the video data stream for the one or more substreams by
checking, for a picture unit of the video data stream, whether the video data stream comprises a substream selection SEI message for the picture unit, and
assigning video coded layer payload packets of the picture unit to a first substream of the one or more substreams, if the video data stream does not comprise a substream selection SEI message for the picture unit, and
if the video data stream comprises a substream selection SEI message for the picture unit, assigning video coded layer payload packets of the picture unit to a substream of the one or more substreams, which substream is indicated by the substream selection SEI message.

9 . Apparatus according to claim 7 , further configured for determining the respective portions for the substreams of the subset of one or more substreams to end at or before an end of a coded video sequence.

10 . Apparatus according to claim 7 , wherein the one or more substreams have an order defined among them, and wherein the apparatus is configured for determining the predetermined portion to be part of a predetermined substream out of the subset of one or more substreams, and configured for
performing the checking the video data stream on trustworthiness sequentially with respect to respective portions of the video data stream derived for the one or more substreams by checking whether the hash value and a further hash value acquired by subjecting a previous portion of the predetermined portion, or further data derived therefrom, to the hash function, fit to the digital signature, or whether a combined hash value derived by hashing the predetermined portion and a further hash value acquired by subjecting a previous portion of the video data stream, or further data derived therefrom, to the hash function, fits to the digital signature, wherein the previous portion precedes the predetermined portion in the sequential order defined among the portions.

11 . Apparatus according to claim 1 , configured for
performing the checking the video data stream on trustworthiness sequentially with respect to a plurality of portions of the video data stream, and further by checking whether the hash value and a further hash value acquired by subjecting a previous portion of the video data stream, or further data derived therefrom, to the hash function, fit to the digital signature, or whether a combined hash value derived by hashing the predetermined portion and a further hash value acquired by subjecting a previous portion of the video data stream, or further data derived therefrom, to the hash function, fits to the digital signa

Assignees

• Fraunhofer Ges Forschung

Inventors

• Pfaff Jonathan
• Hinz Tobias
• Suehring Karsten
• Schwarz Heiko
• Marpe Detlev
• Wiegand Thomas

Classifications

• H04N19/44

  Decoders specially adapted therefor, e.g. video decoders which are asymmetric with respect to the encoder · CPC title

• H04N19/70 Primary

  characterised by syntax aspects related to video coding, e.g. related to compression standards · CPC title

• H04L9/3252

  using DSA or related signature schemes, e.g. elliptic based signatures, ElGamal or Schnorr schemes · CPC title

• H04N21/4408

  involving video stream encryption, e.g. re-encrypting a decrypted video stream for redistribution in a home network · CPC title

• H04N21/2347 Primary

  involving video stream encryption · CPC title