Fast Multiplication on Elliptic Curves over Small Fields of Characteristic Two

We discuss new algorithms for multiplying points on elliptic curves defined over small finite fields of characteristic two. This algorithm is an extension of previous results by Koblitz, Meier, and Staffelbach. Experimental results show that the new methods can give a running time improvement of up to 50 % compared with the ordinary binary algorithm for multiplication. Finally, we present a table of elliptic curves, which are well suited for elliptic curve public key cryptosystems, and for which the new algorithm can be used. Received 14 January 1997 and revised 4 September 1997     

Software-Escrow

Quellcodehinterlegung ist in Deutschland in den letzten Jahren zum üblichen Bestandteil eines wirksamen Risikomanagements geworden. Softwareh?user k?nnen davon genauso profitieren wie deren Kunden. Dieser Artikel erg?nzt auch den Artikel “Escrow Management bei elektronischer Archivierung” von Frau Rechtsanw?ltin Prof. Ursula Sury¹ um die rechtlichen und technischen Aspekte der Quellcodehinterlegung.     

Micro powder-injection moulding of metals and ceramics

Development of micro-MIM/-CIM was started at Forschungszentram Karlsrahe with the aim of creating a process suitable for a wide range of materials as well as for medium-scale and large-scale production of micro components. Using enhanced machine technology and special tempering procedures, this process enables the manufacturing of metal and ceramic devices with smallest wall thicknesses of 50 Μm and structural details of less than 3 Μm. Using ultrafine ceramic powders (e.g. zirconia) and high-quality LIGA mould inserts, surface qualities ofR _a = 40 nm or R_max ≤ 3 mm could be obtained. Possible practical applications are demonstrated by components of micro-annular gear pumps made of zirconia for future handling of very small volumes of dangerous fluids and micro samples (tensile and bending specimens) suitable for mechanical testing of metals (316L, 17-4PH) and ceramic materials (A1₂O₃, ZrO₂) in the micrometre range.     

Micro rotary swaging: process limitations and attempts to their extension

In this paper experimental investigations on micro components that are made by rotary swaging are presented and discussed. At first rotary swaging with its most important process variations is explained basically for the macro scale. Afterwards the fundamental changes of the forming of microcomponents are indicated as well as the smaller machines used henceforth. In this context, the shown process limitations and potential errors are very important. The change in microstructure after rotary swaging is shown in selected geometry and materials. The paper concludes with the planned experimental and analytic investigations as well as the machine design modifications for extension of the process limits of micro rotary swaging.     

Web-Roboter

Ohne Zusammenfassung Eingegangen am 02.04.1998