Welcome to the resource topic for 2024/1166
Title:
On the Relationship between FuncCPA and FuncCPA+
Authors: Takumi Shinozaki, Keisuke Tanaka, Masayuki Tezuka, Yusuke Yoshida
Abstract:Akavia, Gentry, Halevi, and Vald introduced the security notion of function-chosen-plaintext-attack (FuncCPA security) for public-key encryption schemes.
FuncCPA is defined by adding a functional re-encryption oracle to the IND-CPA game.
This notion is crucial for secure computation applications where the server is allowed to delegate a part of the computation to the client.
Dodis, Halevi, and Wichs introduced a stronger variant called FuncCPA$^+.
They showed FuncCPA^+ implies FuncCPA and conjectured that FuncCPA^+$ is strictly stronger than FuncCPA.
They left an open problem to clarify the relationship between these variants.
Contrary to their conjecture, we show that FuncCPA is equivalent to FuncCPA$^+. We show it by two proofs with a trade-off between the number of queries and the number of function inputs. Furthermore, we show these parameters determine the security levels of FuncCPA and FuncCPA^+$.
ePrint: https://eprint.iacr.org/2024/1166
See all topics related to this paper.
Feel free to post resources that are related to this paper below.
Example resources include: implementations, explanation materials, talks, slides, links to previous discussions on other websites.
For more information, see the rules for Resource Topics .