English

Generating k-independent variables in constant time

Data Structures and Algorithms 2014-08-12 v1

Abstract

The generation of pseudorandom elements over finite fields is fundamental to the time, space and randomness complexity of randomized algorithms and data structures. We consider the problem of generating kk-independent random values over a finite field F\mathbb{F} in a word RAM model equipped with constant time addition and multiplication in F\mathbb{F}, and present the first nontrivial construction of a generator that outputs each value in constant time, not dependent on kk. Our generator has period length F\mboxpolylogk|\mathbb{F}|\,\mbox{poly} \log k and uses k\mboxpoly(logk)logFk\,\mbox{poly}(\log k) \log |\mathbb{F}| bits of space, which is optimal up to a \mboxpolylogk\mbox{poly} \log k factor. We are able to bypass Siegel's lower bound on the time-space tradeoff for kk-independent functions by a restriction to sequential evaluation.

Keywords

Cite

@article{arxiv.1408.2157,
  title  = {Generating k-independent variables in constant time},
  author = {Tobias Christiani and Rasmus Pagh},
  journal= {arXiv preprint arXiv:1408.2157},
  year   = {2014}
}

Comments

Accepted to The 55th Annual Symposium on Foundations of Computer Science (FOCS 2014). Copyright IEEE

R2 v1 2026-06-22T05:24:07.144Z