Abstract: In a database query operation, a quantum private query (QPQ) protocol allows a user to determine whether the database provider has been trying to obtain information about their query by performing quantum superpositions of different queries in addition to performing normal queries. This means that, in addition to being able to request the jth or the kth records in the database, the user can also request both records in a quantum superposition. To find out whether the database provider is trying to discover her queries, the user sends proper superpositions of queries and then checks the answer provided by the database to determine whether the superposition has been preserved. If superposition has not been preserved, the user can be confident that the database provider has cheated, and has tried to obtain information on the query.

Abstract: In an address signal decoder for a RAM memory, address signals are decoded in a “bucket brigade” address decoding architecture in which the address signals or bits are sequentially sent along the same address decoding path. The inventive architecture comprises a set of node switches linked into a binary tree. The address signals enter at the root node of the binary tree. As each address signal reaches a node switch at the end the path, it sets the path direction for that switch node so that subsequent address signals that follow the path will use that path direction. The decoder can be used with classical or quantum RAM memories.

Abstract: In an address signal decoder for a RAM memory, address signals are decoded in a “bucket brigade” address decoding architecture in which the address signals or bits are sequentially sent along the same address decoding path. The inventive architecture comprises a set of node switches linked into a binary tree. The address signals enter at the root node of the binary tree. As each address signal reaches a node switch at the end the path, it sets the path direction for that switch node so that subsequent address signals that follow the path will use that path direction. The decoder can be used with classical or quantum RAM memories.

Abstract: In a database query operation, a quantum private query (QPQ) protocol allows a user to determine whether the database provider has been trying to obtain information about their query by performing quantum superpositions of different queries in addition to performing normal queries. This means that, in addition to being able to request the jth or the kth records in the database, the user can also request both records in a quantum superposition. To find out whether the database provider is trying to discover her queries, the user sends proper superpositions of queries and then checks the answer provided by the database to determine whether the superposition has been preserved. If superposition has not been preserved, the user can be confident that the database provider has cheated, and has tried to obtain information on the query.