A tight lower bound for restricted pir protocols
- Cite this article as:
- Beigel, R., Fortnow, L. & Gasarch, W. comput. complex. (2006) 15: 82. doi:10.1007/s00037-006-0208-3
We show that any 1-round 2-server Private Information Retrieval Protocol where the answers are one bit long must ask questions that are at least n−2 bits long, which is nearly equal to the known n−1 upper bound. This improves upon the approximately 0.25n lower bound of Kerenidis and deWolf while avoiding their use of quantum techniques.