Abstract: A database management system (1) comprises up to fifty or more workstations (2), each for a user. The environment may, for example, be a hospital and the system manages medical records in a secure manner. Each user has a private key issued by a KGC (5). A database controller (3) updates a secure database (3) with data and associated signatures generated by the user workstations (2). Thus every record of the secure database (3) has a signature to provide full traceability and non-repudiation of data edits/updates. It is important for the system (1) that the signatures are verified on a regular basis, say every hour. Such a task would be extremely processor-intensive if the database (3) is large. However this is performed by a verification processor (4) of the system (1) in a much shorter time than heretofore, t1+n(&Dgr;), where t1 is the time for one verification, n is the number of signatures, and &Dgr; is a time value which is a very small proportion of t1 (less than 1%).

Abstract: A method of performing IBE cryptography comprising the steps of a key generation server transmitting a master public key to a processor, the processor generating or retrieving a fresh master public key derived from the master public key transmitted by the key generation centre, and the processor using the fresh master public key to generate a public key for transmitting a message to a recipient device having a corresponding private key. The processor may store the fresh master public key in a read only memory for repeated use or it may dynamically generate it. To dynamically generate the fresh master public key the processor multiplies the original master public key by a curve co-factor. The processor may be incorporated into a hand-held card, and it may transfer information to a linked second processor for performing some of the calculations.

Abstract: A method of performing IBE cryptography comprising the steps of a key generation server transmitting a master public key to a processor, the processor generating or retrieving a fresh master public key derived from the master public key transmitted by the key generation centre, and the processor using the fresh master public key to generate a public key for transmitting a message to a recipient device having a corresponding private key. The processor may store the fresh master public key in a read only memory for repeated use or it may dynamically generate it. To dynamically generate the fresh master public key the processor multiplies the original master public key by a curve co-factor. The processor may be incorporated into a hand-held card, and it may transfer information to a linked second processor for performing some of the calculations.

Abstract: A database management system (1) comprises up to fifty or more workstations (2), each for a user. The environment may, for example, be a hospital and the system manages medical records in a secure manner. Each user has a private key issued by a KGC (5). A database controller (3) updates a secure database (3) with data and associated signatures generated by the user workstations (2). Thus every record of the secure database (3) has a signature to provide full traceability and non-repudiation of data edits/updates. It -is important for the system (1) that the signatures are verified on a regular basis, say every hour. Such a task would be extremely processor-intensive if the database (3) is large. However this is performed by a verification processor (4) of the system (1) in a much shorter time than heretofore, t1+n(&Dgr;), where t1 is the time for one verification, n is the number of signatures, and &Dgr; is a time value which is a very small proportion of t1 (less than 1%).