Patent ID: 9679005
Date: 2017-06-13
CPC Classifications: F04C,G06F,H04L

Claim:
1. A client computer for updating a database stored on a server, 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 perform the steps of a) receiving an update first data item, the update first data item comprising a set of successional symbols, b) creating an update suffix item by removing a number of the successional symbols from the left side of the update first data item, the update suffix item being the residual part of the update first data item without the removed symbols, c) encrypting the update suffix item with the suffix cryptographic key for obtaining an encrypted update suffix item and encrypting the update first data item with a first cryptographic key for obtaining an encrypted update first data item, d) providing a storage request to the database, the storage request comprising instructions to store in the database the encrypted update suffix item, the encrypted update first data item and a first referential connection assigning said encrypted update suffix item to the encrypted update first data item, e) repeating steps b)-d) with different numbers of the successional removed symbols, the numbers being in between a minimum and a maximum, wherein the maximum is given by the total number of symbols of the update first data item minus a predefined minimal word length.