Paper 2015/627

On Necessary Padding with IO

Justin Holmgren

Abstract

We show that the common proof technique of padding a circuit before IO obfuscation is sometimes necessary. That is, assuming indistinguishability obfuscation (IO) and one-way functions exist, we define samplers Sam_0, which outputs (aux_0, C_0), and Sam_1, which outputs (aux_1, C_1) such that: - The distributions (aux_0, iO(C_0)) and (aux_1, iO(C_1)) are perfectly distinguishable. - For padding s = poly(lambda)$, the distributions (aux_0, iO(C_0||0^s)) and (aux_1, iO(C_1||0^s)) are computationally indistinguishable. We note this refutes the recent "Superfluous Padding Assumption" of Brzuska and Mittelbach.

Note: updated related work

Metadata
Available format(s)
PDF
Publication info
Preprint. Minor revision.
Keywords
indistinguishability obfuscationpadding
Contact author(s)
holmgren @ csail mit edu
History
2015-08-14: last of 4 revisions
2015-06-30: received
See all versions
Short URL
https://ia.cr/2015/627
License
Creative Commons Attribution
CC BY

BibTeX

@misc{cryptoeprint:2015/627,
      author = {Justin Holmgren},
      title = {On Necessary Padding with IO},
      howpublished = {Cryptology ePrint Archive, Paper 2015/627},
      year = {2015},
      note = {\url{https://eprint.iacr.org/2015/627}},
      url = {https://eprint.iacr.org/2015/627}
}
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