CLIENT COMPUTER FOR QUERYING A DATABASE STORED ON A SERVER VIA A NETWORK

摘要

The invention relates to a client computer for querying a database stored on a server via a network, the server being coupled to the client computer via the network, wherein the database comprises first data items and suffix items, wherein each suffix item describes a suffix of at least one first data item of the first data items, wherein for each suffix item a first referential connection exists in the database assigning said suffix item to the at least one first data item comprising the suffix of said suffix item, wherein each suffix item is encrypted with a suffix cryptographic key in the database, wherein each first data item is encrypted with a first cryptographic key in the database, wherein the client computer has installed thereon an application program, the application program being operational to:
receiving a search request, the search request specifying an infix search expression, said expression comprising a first wildcard term on the left side of a search criterion and a second wildcard term on the right side of the search criterion,transforming the infix search expression into a prefix search expression by disregarding in the search request the first wildcard term and maintaining the search criterion and the second wildcard term,determine a search interval by transforming the prefix search into a corresponding search interval,performing a prefix search by determining all the encrypted suffix items lying within the search interval,providing to the database a request for providing the one or more encrypted first data items being assigned via the first referential connection to the determined encrypted suffix items,receiving from the database the requested encrypted first data items and decrypting said received first data items.

主权项

1. A client computer for querying a database stored on a server via a network, the server being coupled to the client computer via the network, wherein the database comprises first data items and suffix items, wherein each suffix item describes a suffix of at least one first data item of the first data items, wherein for each suffix item a first referential connection exists in the database assigning said suffix item to the at least one first data item comprising the suffix of said suffix item, wherein each suffix item is encrypted with a suffix cryptographic key in the database, wherein each first data item is encrypted with a first cryptographic key in the database, wherein the client computer has installed thereon an application program, the application program being operational to:
receiving a search request, the search request specifying an infix search expression, said expression comprising a first wildcard term on the left side of a search criterion and a second wildcard term on the right side of the search criterion, transforming the infix search expression into a prefix search expression by disregarding in the search request the first wildcard term and maintaining the search criterion and the second wildcard term, determine a search interval by transforming the prefix search into a corresponding search interval, performing a prefix search by determining all the encrypted suffix items lying within the search interval, providing to the database a request for providing the one or more encrypted first data items being assigned via the first referential connection to the determined encrypted suffix items, receiving from the database the requested encrypted first data items and decrypting said received first data items.