  A pay-TV consumer uses a decoder to access encrypted digital content. To this
end, the decoder contains a chip capable of decrypting the content if
provisioned with the appropriate content decryption keys. A key establishment
protocol is used to secure the delivery of the content decryption keys to the
chip. This paper presents a new protocol and shows how the protocol can be
applied in a pay-TV system. Compared to existing protocols, the presented
solution reduces the risk that decoders need to be replaced in order to correct
a security breach. The new protocol has recently been incorporated in an ETSI
standard.
