Abstract: A digital camera equipped with a processor for authentication of images produced from an image file taken by the digital camera is provided. The digital camera processor has embedded therein a private key unique to it, and the camera housing has a public key that is so uniquely related to the private key that digital data encrypted with the private key may be decrypted using the public key. The digital camera processor comprises means for calculating a hash of the image file using a predetermined algorithm, and second means for encrypting the image hash with the private key, thereby producing a digital signature. The image file and the digital signature are stored in suitable recording means so they will be available together. Apparatus for authenticating the image file as being free of any alteration uses the public key for decrypting the digital signature, thereby deriving a secure image hash identical to the image hash produced by the digital camera and used to produce the digital signature.

Abstract: A redundant error-detecting and correcting local area networked computer system (10) having a plurality of nodes (16) each including a network connector board (20') for connecting to an interfacing transceiver (18) attached to a network cable (12, 14). The system comprises a first network cable (12) disposed along a path to interconnect the nodes. The first cable includes a plurality of first interfacing transceivers. A second network cable (14) includes a plurality of second interfacing transceivers. A plurality of three position switches (48) each having a signal input, three outputs for individual selective connection to the input, and a control input for receiving signals designating which of the outputs is to be connected to the signal input are provided. Master switch (50) is provided for receiving directive signals for outputting addressed switch position signals to the three position switches.