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CCS
2005
ACM

Direct chosen ciphertext security from identity-based techniques

10 years 4 months ago
Direct chosen ciphertext security from identity-based techniques
We describe a new encryption technique that is secure in the standard model against adaptive chosen ciphertext (CCA2) attacks. We base our method on two very efficient Identity-Based Encryption (IBE) schemes without random oracles due to Boneh and Boyen, and Waters. Unlike previous CCA2-secure cryptosystems that use IBE as a black box, our approach is endogenous, very simple, and compact. It makes direct use of the underlying IBE structure, and requires no cryptographic primitive other than the IBE scheme itself. This conveys several advantages. We achieve shorter ciphertext size than the best known instantiations of the other methods, and our technique is as efficient as the Boneh and Katz method (and more so than that of Canetti, Halevi, and Katz). Further, our method operates nicely on hierarchical IBE, and since it allows the validity of ciphertexts to be checked publicly, it can be used to construct systems with non-interactive threshold decryption. In this paper we describe two ...
Xavier Boyen, Qixiang Mei, Brent Waters
Added 26 Jun 2010
Updated 26 Jun 2010
Type Conference
Year 2005
Where CCS
Authors Xavier Boyen, Qixiang Mei, Brent Waters
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