Abstract: The present invention relates generally to computer software, and more specifically, to a method and system of making computer software resistant to tampering and reverse-engineering. “Tampering” occurs when an attacker makes unauthorized changes to a computer software program such as overcoming password access, copy protection or timeout algorithms. Broadly speaking, the method of the invention is to increase the tamper-resistance and obscurity of computer software code by transforming the data flow of the computer software so that the observable operation is dissociated from the intent of the original software code. This way, the attacker can not understand and decode the data flow by observing the execution of the code. A number of techniques for performing the invention are given, including encoding software arguments using polynomials, prime number residues, converting variables to new sets of boolean variables, and defining variables on a new n-dimensional vector space.

Abstract: The present invention relates generally to computer software, and more specifically, to a method and system of making computer software resistant to tampering and reverse-engineering. “Tampering ” occurs when an attacker makes unauthorized changes to a computer software program such as overcoming password access, copy protection or timeout algorithms. Broadly speaking, the method of the invention is to increase the tamper-resistance and obscurity of computer software code by transforming the data flow of the computer software so that the observable operation is dissociated from the intent of the original software code. This way, the attacker can not understand and decode the data flow by observing the execution of the code. A number of techniques for performing the invention are given, including encoding software arguments using polynomials, prime number residues, converting variables to new sets of boolean variables, and defining variables on a new n-dimensional vector space.

Abstract: The present invention relates generally to cryptography, and more specifically, to secure authentication of a First Computer Program to a Second Computer Program. The approaches known in the art require that secure data positively identifying Client accounts be stored at a central location, either the Server or a Certifying Authority, requiring large overheads of memory and computational power, and presenting obvious and high-value targets for attacks. The invention provides a means of authenticating Clients to Servers without requiring confidential data to either be stored at the Server, or transmitted to the Server. The Client generates a series of one-time passwords by successive iterations of a non-reversible function on a seed value. The last value in the series is then sent to the Server to establish an account. When the Client wishes to log on to his account, he sends the previous value in the non-reversible series as his password.

Abstract: A device for epitaxial growth of objects by Chemical Vapor Deposition on a substrate comprises a susceptor adapted to receive the substrate and members for heating walls of the susceptor surrounding the substrate and thereby the substrate and a gas mixture fed to the substrate for the growth. The device comprises also members for holding the substrate in the path of the gas mixture through the susceptor at a distance from internal walls thereof.

Abstract: A device for epitaxially growing objects of for instance SiC by Chemical Vapor Deposition on a substrate has a first conduit (24) arranged to conduct substantially only a carrier gas to a room (18) receiving the substrate and a second conduit (25) received in the first conduit, having a smaller cross-section than the first conduit and extending in the longitudinal direction of the first conduit with a circumferential space separating it from inner walls of the first conduit. The second conduit is adapted to conduct substantially the entire flow of reactive gases and it ends as seen in the direction of the flows, and emerges into the first conduit at a distance from said room.