Chosen-ciphertext security from identity-based encryption

D Boneh, R Canetti, S Halevi, J Katz - SIAM Journal on Computing, 2007 - SIAM
SIAM Journal on Computing, 2007SIAM
We propose simple and efficient CCA-secure public-key encryption schemes (ie, schemes
secure against adaptive chosen-ciphertext attacks) based on any identity-based encryption
(IBE) scheme. Our constructions have ramifications of both theoretical and practical interest.
First, our schemes give a new paradigm for achieving CCA-security; this paradigm avoids
“proofs of well-formedness” that have been shown to underlie previous constructions.
Second, instantiating our construction using known IBE constructions we obtain CCA-secure …
We propose simple and efficient CCA‐secure public‐key encryption schemes (i.e., schemes secure against adaptive chosen‐ciphertext attacks) based on any identity‐based encryption (IBE) scheme. Our constructions have ramifications of both theoretical and practical interest. First, our schemes give a new paradigm for achieving CCA‐security; this paradigm avoids “proofs of well‐formedness” that have been shown to underlie previous constructions. Second, instantiating our construction using known IBE constructions we obtain CCA‐secure encryption schemes whose performance is competitive with the most efficient CCA‐secure schemes to date. Our techniques extend naturally to give an efficient method for securing IBE schemes (even hierarchical ones) against adaptive chosen‐ciphertext attacks. Coupled with previous work, this gives the first efficient constructions of CCA‐secure IBE schemes.
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