Paper 2019/1025

On Perfect Correctness without Derandomization

Gilad Asharov, Naomi Ephraim, Ilan Komargodski, and Rafael Pass


We give a method to transform any indistinguishability obfuscator that suffers from correctness errors into an indistinguishability obfuscator that is $\textit{perfectly}$ correct, assuming hardness of Learning With Errors (LWE). The transformation requires sub-exponential hardness of the obfuscator and of LWE. Our technique also applies to eliminating correctness errors in general-purpose functional encryption schemes, but here it is sufficient to rely on the polynomial hardness of the given scheme and of LWE. Both of our results can be based $\textit{generically}$ on any perfectly correct, single-key, succinct functional encryption scheme (that is, a scheme supporting Boolean circuits where encryption time is a fixed polynomial in the security parameter and the message size), in place of LWE. Previously, Bitansky and Vaikuntanathan (EUROCRYPT ’17) showed how to achieve the same task using a derandomization-type assumption (concretely, the existence of a function with deterministic time complexity $2^{O(n)}$ and non-deterministic circuit complexity $2^{\Omega(n)}$) which is non-game-based and non-falsifiable.

Available format(s)
Publication info
Preprint. MINOR revision.
Indistinguishability ObfuscationCorrectnessFunctional Encryption
Contact author(s)
asharov @ cornell edu
nephraim @ cs cornell edu
komargodski @ cornell edu
rafael @ cs cornell edu
2019-09-11: received
Short URL
Creative Commons Attribution


      author = {Gilad Asharov and Naomi Ephraim and Ilan Komargodski and Rafael Pass},
      title = {On Perfect Correctness without Derandomization},
      howpublished = {Cryptology ePrint Archive, Paper 2019/1025},
      year = {2019},
      note = {\url{}},
      url = {}
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