System and method for preventing the unauthorized playback of content

Disclosed herein are systems, methods, and media for preventing the unauthorized playback of content. A system receives, from a client device associated with a user profile, a download authorization start request for an asset for which the user profile is authorized. That system identifies a number of available slots for progressively downloading content. If the number of available slots is greater than zero, the system assigns an available slot from the number of available slots to the client device to yield an assigned slot. That system transmits security information, a download authorization key, and a download authorization duration associated with the assigned slot to the client device in response to the download authorization start request, wherein the security information and download authorization key allow the client device to start a progressive download of the asset for the download authorization duration. At the end of the download authorization, that system terminates the download authorization and releases the assigned slot.