Abstract: Signaling and verifying URL signatures for accessing URL addressable content in adaptive streaming. A plurality of URL authentication and URL authorization descriptors are provided for a plurality of URLs, wherein each URL authentication descriptor comprises information for verification key acquisition and for accessing an authentication tag for authenticating a given URL in the plurality of URLs according to an associated URL authentication scheme. Each URL authorization descriptor is for verification key acquisition and for accessing an authorization tag for authorizing access to content addressable by a given URL in the plurality of URLs according to an associated URL authentication scheme. A plurality of URL authentication and URL authorization descriptors for the plurality of URLs are communicated and each descriptor is verified in the communicated plurality of URL authentication and URL authorization descriptors for its given URL in the plurality of URLs according to its associated scheme.