For example, you can use Private Information Retrieval techniques to privately query a database.
A Private Information Retrieval (PIR) [16] protocol enables to retrieve a specific block from a database without letting the database learn anything about the query and the answer (i.e. neither the index of the block nor the value of the block).
Private information retrieval (PIR) schemes allow a user to retrieve the ith bit of an n-bit data string x, replicated in k⩾2 databases (in the information-theoretic setting) or in k⩾1 databases (in the computational setting), while keeping the value of i private.
Let (Gen, Enc, Dec) be a semantically secure (IND-CPA, [29]) public key cryptosystem, let Q u e r y D B P I R be the retrieve query from a database DB of a Private Information Retrieval protocol and let U p d a t e D B P I S ( v a l, i ) be the write query into a database DB (that adds val to the i-th field) of a Private Information Storage protocol.
A Private Information Retrieval protocol (PIR, [12]) is a scheme that enables to retrieve a specific information from a remote server in such a way that the latter does not learn information about the query.
Private information retrieval (PIR) is normally modeled as a game between two players: a user and a database.
As a class of one-sided two-party computation, unconditionally secure symmetrically private information retrieval (SPIR) is impossible.
So the study of quantum symmetrically private information retrieval (QSPIR), i.e., quantum private query (QPQ) with an interesting degree of security is desirable.
Another idea is "private information retrieval", which allows excerpts from a database to be made available in confidence.But all these processes come at some cost.
COS 533 Advanced Cryptography This course covers a selection of advanced topics in cryptography, including some or all of the following: fully homomorphic encryption, zero knowledge proofs, traitor tracing, identity-based encryption, private information retrieval, garbled circuits, secret sharing, multiparty computation, lattice-based cryptography, and elliptic curve-based cryptography.
