Abstract: In various embodiments, a server may be provided. The server may respond to a request for a service, from a processing device, with a challenge. The challenge may include a partial key for a memory-intensive operation, a number of iterations of the memory-intensive operation to perform, and a result of performing the number of iterations of the memory-intensive operation. Upon receiving the challenge, the processing device may choose a complete key consistent with the partial key and may produce a proposed result by performing the memory-intensive operation for the number of iterations. When the proposed result matches the result included in the challenge, the processing device may send a challenge answer, including the chosen complete key, to the server. Upon receiving a correct challenge answer from the processing device, the server may access the requested service and may return a result of the access to the processing device.

Abstract: A method for manufacturing surgical blades from either a crystalline or poly-crystalline material, preferably in the form of a wafer, is disclosed. The method includes preparing the crystalline or poly-crystalline wafers by mounting them and machining trenches into the wafers. The methods for machining the trenches, which form the bevel blade surfaces, include a diamond blade saw, laser system, ultrasonic machine, and a hot forge press. The wafers are then placed in an etchant solution which isotropically etches the wafers in a uniform manner, such that layers of crystalline or poly-crystalline material are removed uniformly, producing single or double bevel blades. Nearly any angle can be machined into the wafer which remains after etching. The resulting radii of the blade edges is 5-500 nm, which is the same caliber as a diamond edged blade, but manufactured at a fraction of the cost.

Abstract: A method is provided of forming a light sensing arrangement for use in a light sensor. The method comprises tiling a plurality of individual light sensing elements on a carrier, each element having a notch formed in an edge thereof, the notch being adapted to provide space, when the elements are tiled together, for an electrical connection to be made between the carrier and a surface of the element arranged to faced away from the carrier. Each element may comprise Silicon Photomultiplier (SPM) circuitry.

Abstract: A method for manufacturing blades for surgical and other uses from either a crystalline or polycrystalline material, preferably in the form of a wafer, comprises preparing the crystalline or polycrystalline wafers by mounting them and machining trenches into the wafers. The methods for machining the trenches, which form the bevel blade surfaces, include a diamond blade saw, laser system, ultrasonic machine, a hot forge press and a router. When a router is used, through-holes are drilled in the wafer to define the starting locations of the trenches. After the trenches are formed, the wafers are placed in an etchant solution which isotropically etches the wafers in a uniform manner, such that layers of crystalline or polycrystalline material are removed uniformly, producing single or double bevel blades, with each bevel having one or more facets. Nearly any bevel angle can be machined into the wafer which remains after etching.