Patent ID: 9270461
Filing Date: 2016-02-23
CPC Classification: G06F,H04L,H04N

Claim Text:
1. A method for communicating encryption information in template mode in dynamic adaptive streaming over hypertext transfer protocol (DASH), the method comprising: sending in a media presentation description (MPD), from a network server to a client, a template for generating a universal resource locator (URL) to obtain an initialization vector (IV) that is used for encrypting a segment, wherein the segment is associated with a cryptoperiod where a plurality of segments are encrypted with the same encryption parameters; including, in the MPD, a CryptoTimeline element for deriving one or more cryptoperiods at the client using run-length coding, the CryptoTimeline element indicating a sequence of cryptoperiods of constant duration each including the same number of segments, wherein the CryptoTimeline element includes a first optional attribute for indicating a number of constant-duration cryptoperiods within a timeline, a second mandatory attribute for indicating, by a number of segments, a cryptoperiod duration of every period in the timeline, and a third optional attribute for indicating a number of segments between the end of a previous CryptoTimeline element and the timeline; in absence of an IV value in the MPD, receiving from the client a URL for the IV configured according to the IV URL template associated with at least one of the one or more cryptoperiods within the timeline; and upon receiving the IV URL, returning an IV value corresponding to the IV URL to the client for decrypting each of the plurality of segments associated with the at least one cryptoperiod.