Security with Functional Re-Encryption from CPA

ePrint Report: Security with Functional Re-Encryption from CPA

Yevgeniy Dodis, Shai Halevi, Daniel Wichs

The notion of functional re-encryption security (funcCPA) for public-key encryption schemes was recently introduced by Akavia et al. (TCC'22), in the context of homomorphic encryption. This notion lies in between CPA security and CCA security: we give the attacker a functional re-encryption oracle instead of the decryption oracle of CCA security. This oracle takes a ciphertext $c$ and a function $f$, and returns fresh encryption of …

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