English

Lower Bound on the Redundancy of PIR Codes

Information Theory 2017-03-01 v2 math.IT

Abstract

We prove that the redundancy of a kk-server PIR code of dimension ss is Ω(s)\Omega(\sqrt{s}) for all k3k \ge 3. This coincides with a known upper bound of O(s)O(\sqrt{s}) on the redundancy of PIR codes. Moreover, for k=3k=3 and k=4k = 4, we determine the lowest possible redundancy of kk-server PIR codes exactly. Similar results were proved independently by Mary Wootters using a different method.

Keywords

Cite

@article{arxiv.1605.01869,
  title  = {Lower Bound on the Redundancy of PIR Codes},
  author = {Sankeerth Rao and Alexander Vardy},
  journal= {arXiv preprint arXiv:1605.01869},
  year   = {2017}
}