Paper 2015/114

Weak Ideal Functionalities for Designing Random Oracles with Applications to Fugue

Shai Halevi, William E. Hall, Charanjit S. Jutla, and Arnab Roy


We define ideal functionalities that are weaker than ideal functionalities traditionally used in realizing variable input length (VIL) random oracles (RO) in the indifferentiability or universal-Composability (UC) model. We also show realization of VIL-RO using these weaker ideal functionalities, with applications to proving Fugue and CubeHash hash functions to be VIL-RO. We argue that components of Fugue realize this weaker ideal functionality using techniques employed in proving resistance of Fugue to differential collision-attacks. This should be contrasted with other hash functions that are proven VIL-RO assuming the components are extremely ideal, e.g. random permutations.

Note: Added Contact address.

Available format(s)
Secret-key cryptography
Publication info
Preprint. MINOR revision.
FugueRandom OracleUCHash Function
Contact author(s)
csjutla @ us ibm com
2015-02-24: revised
2015-02-24: received
See all versions
Short URL
Creative Commons Attribution


      author = {Shai Halevi and William E.  Hall and Charanjit S.  Jutla and Arnab Roy},
      title = {Weak Ideal Functionalities for Designing Random Oracles with Applications to Fugue},
      howpublished = {Cryptology ePrint Archive, Paper 2015/114},
      year = {2015},
      note = {\url{}},
      url = {}
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