Sciweavers

26
Voted
STOC
2003
ACM

Extractors: optimal up to constant factors

14 years 7 months ago
Extractors: optimal up to constant factors
This paper provides the first explicit construction of extractors which are simultaneously optimal up to constant factors in both seed length and output length. More precisely, for every n, k, our extractor uses a random seed of length O(log n) to transform any random source on n bits with (min-)entropy k, into a distribution on (1 - )k bits that is -close to uniform. Here and can be taken to be any positive constants. (In fact, can be almost polynomially small). Our improvements are obtained via three new techniques, each of which may be of independent interest. The first is a general construction of mergers [22] from locally decodable error-correcting codes. The second introduces new condensers that have constant seed length (and retain a constant fraction of the min-entropy in the random source). The third is a way to augment the "win-win repeated condensing" paradigm of [17] with error reduction techniques like [15] so that the our constant seed-length condensers can be...
Chi-Jen Lu, Omer Reingold, Salil P. Vadhan, Avi Wi
Added 03 Dec 2009
Updated 03 Dec 2009
Type Conference
Year 2003
Where STOC
Authors Chi-Jen Lu, Omer Reingold, Salil P. Vadhan, Avi Wigderson
Comments (0)