Quantum Circuit Design and Analysis for Database Search Applications

Abstract

In this paper, we show how quantum Boolean circuits can be used to implement the oracle and the inversion-about-average function in Grover's search algorithm. Before illustrating how this can be done, we present the circuit design principle using the satisfiability (SAT) problem as an example. Then, based on this principle, we show the quantum circuits for two different kinds of applications. The first one is searching a phone book. Although this is a typical example of Grover's algorithm, we show that it is impractical as a real-world application. As the second application, we give the quantum circuits for a more practical application-breaking a symmetric cryptosystem. Although these two applications have quite different types of search criteria, they are both one-way functions and the proposed circuits can actually be generalized to any such problems. In this perspective, we conclude this paper by proposing a template of quantum circuits that is capable of searching the solution of a certain class of one-way functions.

Intelligent pharmaceutical patent search on a near-term gate-based quantum computer

“…We found some general techniques that can reduce the circuit size, although they have some side effects. For example, we can reduce the circuit by encoding the patent as a 3-SAT problem and then designing a quantum circuit from the 3-SAT problem 43 . For example, if we have three search items , we can use multiple MCX gates to mark the search items, as shown in Supplementary Fig.…”

Optimized methods for inserting and deleting records and data retrieving in quantum database

“…Step [7], and a deletion when 1 . In particular, when 1 3 , the deletion is optimal since it is made with certainty for high data size [4].…”

“…Searching items with respect to specific oracle were proposed by I.Y.L. Ju et al [7], they showed a circuit based implementation of the Grover's algorithm used for the database search process; but data basic operations like INSERT and DELETE have not been addressed.…”

CNOT-based design and query management in quantum relational databases

“…The SELECT query was deeply treated by Ju et al, 2 where they suggested a detailed CNOT-based circuit design that realizes the Grover's algorithm. Hu et al 3 proposed how to digitize the database itself to treat the search queries as a sequence of calls to factorized quantum search algorithm.…”