Paper 2007/127
CCA2-Secure Threshold Broadcast Encryption with Shorter Ciphertexts
Vanesa Daza, Javier Herranz, Paz Morillo, and Carla Ràfols
Abstract
In a threshold broadcast encryption scheme, a sender chooses (ad-hoc) a set of $n$ receivers and a threshold $t$, and then encrypts a message by using the public keys of all the receivers, in such a way that the original plaintext can be recovered only if at least $t$ receivers cooperate. Previously proposed threshold broadcast encryption schemes have ciphertexts whose length is $\O(n)$. In this paper, we propose new schemes, for both PKI and identity-based scenarios, where the ciphertexts' length is $\O(n-t)$. The construction uses secret sharing techniques and the Canetti-Halevi-Katz transformation to achieve chosen-ciphertext security. The security of our schemes is formally proved under the Decisional Bilinear Diffie-Hellman (DBDH) Assumption.
Metadata
- Available format(s)
-
PDF
PS
- Category
- Cryptographic protocols
- Publication info
- Published elsewhere. Unknown where it was published
- Keywords
- threshold broadcast encryptionad-hoc groupssecret sharing
- Contact author(s)
- jherranz @ iiia csic es
- History
- 2007-04-04: received
- Short URL
- https://ia.cr/2007/127
- License
-
CC BY
BibTeX
@misc{cryptoeprint:2007/127,
author = {Vanesa Daza and Javier Herranz and Paz Morillo and Carla Ràfols},
title = {{CCA2}-Secure Threshold Broadcast Encryption with Shorter Ciphertexts},
howpublished = {Cryptology {ePrint} Archive, Paper 2007/127},
year = {2007},
url = {https://eprint.iacr.org/2007/127}
}
