# Shared generation of pseudo-random functions

Wang, Huaxiong & Pieprzyk, Josef
(2004)
Shared generation of pseudo-random functions.
*Journal of Complexity*, *20*(2-3), pp. 458-472.

## Abstract

In Crypto’95, Micali and Sidney proposed a method for shared generation of a pseudo-random function f(·) among n players in such a way that for all the inputs x, any u players can compute f(x) while t or fewer players fail to do so, where 0⩽t<u⩽n. The idea behind the Micali–Sidney scheme is to generate and distribute secret seeds S={s1,…,sd} of a poly-random collection of functions, among the n players, each player gets a subset of S, in such a way that any u players together hold all the secret seeds in S while any t or fewer players will lack at least one element from S. The pseudo-random function is then computed as

where fsi(·)'s are poly-random functions. One question raised by Micali and Sidney is how to distribute the secret seeds satisfying the above condition such that the number of seeds, d, is as small as possible.

In this paper, we continue the work of Micali and Sidney. We first provide a general framework for shared generation of pseudo-random function using cumulative maps. We demonstrate that the Micali–Sidney scheme is a special case of this general construction. We then derive an upper and a lower bound for d. Finally we give a simple, yet efficient, approximation greedy algorithm for generating the secret seeds S in which d is close to the optimum by a factor of at most u ln 2.

Impact and interest:

**Citation counts** are sourced monthly from **Scopus** and **Web of Science®** citation databases.

These databases contain citations from different subsets of available publications and different time periods and thus the citation count from each is usually different. Some works are not in either database and no count is displayed. Scopus includes citations from articles published in 1996 onwards, and Web of Science® generally from 1980 onwards.

Citations counts from the **Google Scholar™** indexing service can be viewed at the linked Google Scholar™ search.

ID Code: | 74363 |
---|---|

Item Type: | Journal Article |

Refereed: | Yes |

DOI: | 10.1016/j.jco.2003.08.021 |

ISSN: | 0885-064x |

Divisions: | Current > QUT Faculties and Divisions > Science & Engineering Faculty |

Deposited On: | 23 Jul 2014 04:00 |

Last Modified: | 28 Jul 2014 00:30 |

Export: EndNote | Dublin Core | BibTeX

Repository Staff Only: item control page