Volume 8 (2012) Article 16 pp. 369-374 [Note]
Quantum Private Information Retrieval with Sublinear Communication Complexity
This note presents a quantum protocol for private information retrieval, in the case of a single (honest) server and with information-theoretical privacy, that has $O(\sqrt{n})$-qubit communication complexity, where $n$ denotes the size of the database. In comparison, it is known that any classical protocol must use $\Omega(n)$ bits of communication in this setting.