---
res:
  bibo_abstract:
  - Witness encryption (WE) was introduced by Garg et al. [GGSW13]. A WE scheme is
    defined for some NP language L and lets a sender encrypt messages relative to
    instances x. A ciphertext for x can be decrypted using w witnessing x ∈ L, but
    hides the message if x ∈ L. Garg et al. construct WE from multilinear maps and
    give another construction [GGH+13b] using indistinguishability obfuscation (iO)
    for circuits. Due to the reliance on such heavy tools, WE can cur- rently hardly
    be implemented on powerful hardware and will unlikely be realizable on constrained
    devices like smart cards any time soon. We construct a WE scheme where encryption
    is done by simply computing a Naor-Yung ciphertext (two CPA encryptions and a
    NIZK proof). To achieve this, our scheme has a setup phase, which outputs public
    parameters containing an obfuscated circuit (only required for decryption), two
    encryption keys and a common reference string (used for encryption). This setup
    need only be run once, and the parame- ters can be used for arbitrary many encryptions.
    Our scheme can also be turned into a functional WE scheme, where a message is
    encrypted w.r.t. a statement and a function f, and decryption with a witness w
    yields f (m, w). Our construction is inspired by the functional encryption scheme
    by Garg et al. and we prove (selective) security assuming iO and statistically
    simulation-sound NIZK. We give a construction of the latter in bilinear groups
    and combining it with ElGamal encryption, our ciphertexts are of size 1.3 kB at
    a 128-bit security level and can be computed on a smart card.@eng
  bibo_authorlist:
  - foaf_Person:
      foaf_givenName: Hamza M
      foaf_name: Abusalah, Hamza M
      foaf_surname: Abusalah
      foaf_workInfoHomepage: http://www.librecat.org/personId=40297222-F248-11E8-B48F-1D18A9856A87
  - foaf_Person:
      foaf_givenName: Georg
      foaf_name: Fuchsbauer, Georg
      foaf_surname: Fuchsbauer
      foaf_workInfoHomepage: http://www.librecat.org/personId=46B4C3EE-F248-11E8-B48F-1D18A9856A87
  - foaf_Person:
      foaf_givenName: Krzysztof Z
      foaf_name: Pietrzak, Krzysztof Z
      foaf_surname: Pietrzak
      foaf_workInfoHomepage: http://www.librecat.org/personId=3E04A7AA-F248-11E8-B48F-1D18A9856A87
    orcid: 0000-0002-9139-1654
  bibo_doi: 10.1007/978-3-319-39555-5_16
  bibo_volume: 9696
  dct_date: 2016^xs_gYear
  dct_identifier:
  - UT:000386324500016
  dct_language: eng
  dct_publisher: Springer@
  dct_title: Offline witness encryption@
...