Paper 2015/487

Contention in Cryptoland: Obfuscation, Leakage and UCE

Mihir Bellare, Igors Stepanovs, and Stefano Tessaro


This paper addresses the fundamental question of whether or not different, exciting primitives now being considered actually exist. We show that we, unfortunately, cannot have them all. We provide results of the form not(A) OR not(B), meaning one of the primitives A,B cannot exist. (But we don't know which.) Specifically, we show that: (1) VGBO (Virtual Grey Box Obfuscation) for all circuits, which has been conjectured to be achieved by candidate constructions, cannot co-exist with Canetti's 1997 AI-DHI (auxiliary input DH inversion) assumption, which has been used to achieve many goals including point-function obfuscation (2) iO (indistinguishability obfuscation) for all circuits cannot co-exist with KM-LR-SE (key-message leakage-resilient symmetric encryption) (3) iO cannot co-exist with hash functions that are UCE secure for computationally unpredictable split sources.

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Publication info
A minor revision of an IACR publication in TCC 2016
impossibility resultsassumptionsobfuscationVGBOAI-DHI assumptionleakageUCE
Contact author(s)
istepano @ eng ucsd edu
2015-11-03: last of 3 revisions
2015-05-22: received
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      author = {Mihir Bellare and Igors Stepanovs and Stefano Tessaro},
      title = {Contention in Cryptoland: Obfuscation, Leakage and UCE},
      howpublished = {Cryptology ePrint Archive, Paper 2015/487},
      year = {2015},
      note = {\url{}},
      url = {}
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