United States Patent 6,163,841 Venkatesan , et al. December 19, 2000 Technique for producing privately authenticatable cryptographic signatures and for authenticating such signatures Abstract A technique for generating, for a given message to be signed, an authentic cryptographic signature that can be authenticated, by a recipient of the signed message, as having originated from a signor of the message; and appropriately authenticating such a signature. Specifically, this technique, given a message, such as, e.g., a numerical product copy identifier (83, 93), forms an authentic signature (87, 97), based on public-key cryptosystem, through use of generator value selected from points on an elliptic curve over a finite field. The authentic signature is generated using the generator value in conjunction with three keys; namely, a public key, a private key and a secret key, and thus substantially increases the security associated with cryptographic signatures generated through a conventional two-key public-key cryptosystem. A unique product copy indicia can be formed by concatenating the identifier, for a given product copy, with its corresponding authentic signature. During subsequent user installation of that copy to a computer, the user enters the indicia when prompted by execution of an installation program which, in turn, privately authenticates the signature contained in the indicia in order to continue or prematurely terminate the installation. Inventors: Venkatesan; Ramarathnam R. (Bellevue, WA); Montgomery; Peter L. (San Rafael, CA) Assignee: Microsoft Corporation (Redmond, WA) Appl. No.: 102851 Filed: June 23, 1998 Link: (May be wrapped into garbage. Use patented cut'n paste technology to restore) http://164.195.100.11/netacgi/nph-Parser?Sect1=PTO1&Sect2=HITOFF&d=PALL&p=1&u=/netahtml/srchnum.htm&r=1&f=G&l=50&s1='6,163,841'.WKU.&OS=PN/6,163,841&RS=PN/6,163,841 Yours Bo Elkjaer, Denmark -- [ ... Bevar naturen: Sylt et egern... <-- ]