Abstract: The present disclosure relates to a method for accessing a database stored on a server using a relation. The server is coupled to a client computer via a network, wherein the relation comprises first data items, the first data items forming a partially ordered set in the first relation, wherein for each first data item a referential connection exists in the database assigning said first data item to at least one second data item of the database. The method comprises: identifying first data items of the relation referencing N second data items; for each identified first data item modifying, using a same modification method, the identified first data item M times, wherein M?N, for obtaining M unique modified data items; associating with each of modified first data items of a given first data item a respective portion of the N referential connections of the given first data item; inserting the modified first data items in the relation, thereby replacing the identified first data items.

Abstract: A method comprises predefining a reference data item; creating a relation and inserting a given data item of the set of data items into the relation; inserting each data item of the set of data items into the created relation using a traversal method, wherein the order comparing step comprises in case a comparison result of the currently traversed data item with the reference data item is different from a comparison result of the to be inserted data item with the reference data item inverting the decision logic, and using the inverted decision logic in the decision step; and providing the created relation.

Abstract: The present disclosure relates to a method for accessing a database stored on a server using a relation. The server is coupled to a client computer via a network, wherein the relation comprises first data items, the first data items forming a partially ordered set in the first relation, wherein for each first data item a referential connection exists in the database assigning said first data item to at least one second data item of the database. The method comprises: identifying first data items of the relation referencing N second data items; for each identified first data item modifying, using a same modification method, the identified first data item M times, wherein M?N, for obtaining M unique modified data items; associating with each of modified first data items of a given first data item a respective portion of the N referential connections of the given first data item; inserting the modified first data items in the relation, thereby replacing the identified first data items.

Abstract: The present disclosure relates to a method for securing access to a first relation. The first relation comprises data items. The data items form a partially ordered set in the first relation. The method comprises: predefining a reference data item; creating a relation and inserting a given data item of the set of data items into the relation; inserting each data item of the set of data items into the created relation using the traversal method, wherein the order comparing step comprises in case a comparison result of the currently traversed data item with the reference data item is different from a comparison result of the to be inserted data item with the reference data item inverting the decision logic, and using the inverted decision logic in the decision step; and providing the created relation.

Abstract: The invention relates to method for querying a database stored on a server network, the server being coupled to the client computer via the network, wherein the database comprises a relation, the relation comprising data items, the data items forming a partially ordered set in the relation, the method comprising receiving at the client a request for a data operation on a desired data item, the method comprising a. determining as an initial version number of the data items a currently valid version number of the data items, b.

Abstract: A method includes an algorithm that is adapted for resorting sorted data items in accordance with levels and the ordering of the nodes within each level of a tree data structure, each data item corresponding to a node of the tree data. The items are received at a client computer, and to be stored on the tree data structure. The received data items are sorted in accordance with a predefined sorting order. The algorithm is processed at the client computer for resorting the sorted received data items. A data table is generated for representing the tree data structure in a tabular form having columns and rows, wherein in accordance with the resorting order each row of the data table represents a respective resorted data item, wherein values in the columns are determined in accordance with the order of the rows. The data table is stored as the tree data structure.

Abstract: The present disclosure relates to a computer system for inserting multiple data items in a relation, the relation being stored on a server computer of the computer system, the relation comprising data items, wherein the data items are encrypted with a first encryption method in the relation, wherein the data items form a partially ordered set in the relation, the partial order being formed with respect to the data items in non-encrypted form.

Abstract: The present disclosure relates to transmitting a request for a set of data records, the request indicating encrypted data items associated with first and second interval boundaries, and selectively traversing a partially ordered set to determine an encrypted data item of the partially ordered set that is associated with an interval boundary of the first and second interval boundaries, based on no cache entries being associated with any encrypted data item associated with the interval boundary. The selectively traversing may include decrypting one or more portions of the partially ordered set, determining the encrypted data item of the partially ordered set, and transmitting a request to retrieve a data element of a linear order annotated to the encrypted data item of the partially ordered set associated with the interval boundary, to cause generation of a new cache entry including the encrypted data item and the data element.

Abstract: The present disclosure relates to transmitting a request for a set of data records, the request indicating encrypted data items associated with first and second interval boundaries, and selectively traversing a partially ordered set to determine an encrypted data item of the partially ordered set that is associated with an interval boundary of the first and second interval boundaries, based on no cache entries being associated with any encrypted data item associated with the interval boundary. The selectively traversing may include decrypting one or more portions of the partially ordered set, determining the encrypted data item of the partially ordered set, and transmitting a request to retrieve a data element of a linear order annotated to the encrypted data item of the partially ordered set associated with the interval boundary, to cause generation of a new cache entry including the encrypted data item and the data element.

Abstract: The present disclosure relates to transmitting a request for a set of data records, the request indicating encrypted data items associated with first and second interval boundaries, and selectively traversing a partially ordered set to determine an encrypted data item of the partially ordered set that is associated with an interval boundary of the first and second interval boundaries, based on no cache entries being associated with any encrypted data item associated with the interval boundary. The selectively traversing may include decrypting one or more portions of the partially ordered set, determining the encrypted data item of the partially ordered set, and transmitting a request to retrieve a data element of a linear order annotated to the encrypted data item of the partially ordered set associated with the interval boundary, to cause generation of a new cache entry including the encrypted data item and the data element.

Abstract: The invention relates to a client computer for updating a first relation in a database stored on a server via a network with an update first data item, the server being coupled to the client computer via the network, wherein the first data items are encrypted with a first cryptographic key in the first relation, wherein the first data items form a partially ordered set in the first relation, the partial order being formed with respect to the first data items in non-encrypted form, wherein the client computer has installed thereon an application program, the application program being operational to perform the steps of sequentially requesting and decrypting encrypted first data items and providing a storage request to the data base in case a position for storing the update first data item is determined.

Abstract: The invention relates to a client computer for updating a database stored on a server via a network, the server being coupled to the client computer via the network, wherein the database comprises a set of first relations, wherein each first relation in the set of the first relations comprises first data items, wherein for each first relation the first data items are encrypted with a respective first cryptographic key in the first relation, wherein the first data items form a partially ordered set in each first relation, in each first relation the partial order being formed with respect to the first data items of said first relation in non-encrypted form.

Abstract: The invention relates to a client computer for updating 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 a postfix search on a search criterion, determining the suffix item matching the search criterion, providing to the database a request for provi

Abstract: The invention relates to a method for creating a set of asymmetrical cryptographic key pairs, wherein the set of key pairs has a first key pair (K1) and a second key pair (K2), wherein the first key pair is formed by a first private (G1) and a first public key (O1) and the second key pair is formed by a second private (G2) and a second public key (O2), wherein a first cipher (C_G2_O1) is allocated to the first and second key pair, wherein the first cipher is formed by an encryption of the second private key (G2) with the first public key (O1), having the following steps: adding a third asymmetrical cryptographic key pair (K3) to the set of key pairs, wherein the third key pair is formed by a third private (G3) and a third public key (O3); creating a second cipher (C_G3_O1) by encrypting the third private key (G3) with the first public key (O1); storing the second cipher (212; 186), wherein the set of key pairs has a directed graph structure.

Abstract: 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 o

Abstract: 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 a postfix search on a search criterion, determining the suffix item matching the search criterion, providing to the database a request for provi

Abstract: A computer system is disclosed herein for storage and retrieval of encrypted data items, such as for storing encrypted data items in the cloud, as well as a respective client computer, client computer system, computer program product and computer-implemented method. Embodiments of the disclosed computer system allow for searching for encrypted data items stored in a database based on functional values associated with the data items. The retrieval of the data items from the database can be performed without knowledge of a respective cryptographic key by the database.

Abstract: 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 a first relation, wherein the first relation comprises first data items, wherein the first data items are encrypted with a first cryptographic key in the first relation, wherein the first data items form a partially ordered set in the first relation, the partial order being formed with respect to the first data items in non-encrypted form, wherein the client computer has installed thereon an application program, the application program being operational to perform the steps of receiving a search request specifying a search interval and determining the first data item forming an interval boundary of the search interval.