Trustworthiness of video data streams
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.
1 . Apparatus for checking a video data stream having a video encoded thereinto on trustworthiness, wherein the apparatus comprises:
a processor, configured for
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; and further configured for:
deriving an overview supplemental enhancement information message from the video data stream, the overview supplemental enhancement information 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 includes a substream selection supplemental enhancement information 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 include a substream selection supplemental enhancement information message for the picture unit, and
if the video data stream includes a substream selection supplemental enhancement information 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 supplemental enhancement information message.
2 . Apparatus according to claim 1 , wherein the digital signature is transmitted in a 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 obtain 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 , wherein the digital signature is fitted to by a predetermined value in case of
an equality of the predetermined value with a check value obtained by decrypting the digital signature, or a predetermined portion of the check value associated with the predetermined value, or
an equality with the check value in a further hashed domain, reached by a further hash function applied onto the predetermined value or a concatenation of value including the predetermined value.
6 . Apparatus according to claim 1 , configured for performing the checking by use of an asymmetric decryption scheme using a public key.
7 . Apparatus according to claim 1 , wherein the hash value depends on every bit of the predetermined portion of the video data stream in an entropy coded domain.
8 . Apparatus according to claim 1 , wherein the predetermined portion of the video data stream extends over more than one access unit of the video data stream so that the hash value depends on bits of the more than one access unit.
9 . Apparatus for rendering a video data stream having a video encoded thereinto checkable on trustworthiness, wherein the apparatus comprises:
a processor, configured for
subjecting a predetermined portion of the video data stream, or data derived therefrom, to a hash function to obtain a hash value;
computing a digital signature based on the hash value so as to digitally sign the hash value, and
inserting the digital signature into the video data stream, thereby allowing determining whether the video data stream is trustworthy by checking whether the hash value fits to the digital signature; and further configured for
inserting an overview supplemental enhancement information message into the video data stream, the overview supplemental enhancement information 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
rendering the video data stream checkable on trustworthiness with respect to a subset of one or more substreams of the one or more substreams, so that respective portions of the video data stream for the one or more substreams are to be located in the video data stream by
checking, for a picture unit of the video data stream, whether the video data stream includes a substream selection supplemental enhancement information 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 include a substream selection supplemental enhancement information message for the picture unit, and
if the video data stream includes a substream selection supplemental enhancement information 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 supplemental enhancement information message.
10 . Method for checking a video data stream having a video encoded thereinto on trustworthiness, wherein the method 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;
checking whether the hash value fits to the digital signature to determine whether the video data stream is trustworthy;
deriving an overview supplemental enhancement information message from the video data stream, the overview supplemental enhancement information 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 includes a substream selection supplemental enhancement information 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 include a substream selection supplemental enhancement information message for the picture unit, and
if the video data stream includes a substream selection supplemental enhancement information 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 supplemental enhancement information message.
11 . Non-transitory digital storage medium having stored thereon a video data stream, wherein the video data stream has a video encoded thereinto by a method for rendering a video data stream having a video encoded thereinto checkable on trustworthiness, the method comprising:
subjecting a predetermined portion of the video data stream, or data derived therefrom, to a hash function to obtain a hash value;
computing a digital signature based on the hash value so as to digitally sign the hash value,
inserting the digital signature into the video data stream, thereby allowing determining whether the video data stream is trustworthy by checking whether the hash value fits to the digital signature;
inserting an overview supplemental enhancement information message into the video data stream, the overview supplemental enhancement information 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
rendering the video data stream checkable on trustworthiness with respect to a subset of one or more substreams of the one or more substreams, so that respective portions of the video data stream for the one or more substreams are to be located in the video data stream by
checking, for a picture unit of the video data stream, whether the video data stream includes a substream selection supplemental enhancement information 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 include a substream selection supplemental enhancement information message for the picture unit, and
if the video data stream includes a substream selection supplemental enhancement information 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 supplemental enhancement information message.