Extended DLNA protocol: Sharing protected pay TV contents

DLNA can be considered as a good candidate for sharing protected contents among authorized devices. There is a important penetration of DLNA certified devices, and it offers link protection. We identify problems on DLNA´s link protection, DTCP-IP, and we propose to improve the authentication and key derivation mechanism. DLNA sharing can be extended to include pre and post acquisition protection content at the price of inexpensive descrambler.