Paper 2012/307

Multi-Channel Broadcast Encryption

Duong Hieu Phan, David Pointcheval, and Viet Cuong Trinh


Broadcast encryption aims at sending a content to a large arbitrary group of users at once. Currently, the most efficient schemes provide constant-size headers, that encapsulate ephemeral session keys under which the payload is encrypted. However, in practice, and namely for pay-TV, providers have to send various contents to different groups of users. Headers are thus specific to each group, one for each channel: as a consequence, the global overhead is linear in the number of channels. Furthermore, when one wants to zap to and watch another channel, one has to get the new header and decrypt it to learn the new session key: either the headers are sent quite frequently or one has to store all the headers, even if one watches one channel only. Otherwise, the zapping time becomes unacceptably long. In this paper, we consider encapsulation of several ephemeral keys, for various groups and thus various channels, in one header only, and we call this new primitive Multi-Channel Broadcast Encryption: one can hope for a much shorter global overhead and a short zapping time since the decoder already has the information to decrypt any available channel at once. Our candidates are private variants of the Boneh-Gentry-Waters scheme, with a constant-size global header, independently of the number of channels. In order to prove the CCA security of the scheme, we introduce a new dummy-helper technique and implement it in the random oracle model.

Available format(s)
Cryptographic protocols
Publication info
Published elsewhere. Unknown where it was published
broadcast encryption
Contact author(s)
phan @ di ens fr
2012-06-03: received
Short URL
Creative Commons Attribution


      author = {Duong Hieu Phan and David Pointcheval and Viet Cuong Trinh},
      title = {Multi-Channel Broadcast Encryption},
      howpublished = {Cryptology ePrint Archive, Paper 2012/307},
      year = {2012},
      note = {\url{}},
      url = {}
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