04868877 is referenced by 415 patents and cites 10 patents.

A public key cryptographic system is disclosed with enhanced digital signature certification which authenticates the identity of the public key holder. A hierarchy of nested certifications and signatures are employed which indicate the authority and responsibility levels of the individual whose signature is being certified. The present invention enhances the capabilities of public key cryptography so that it may be employed in a wider variety of business transactions, even those where two parties may be virtually unknown to each other. Counter-signature and joint-signature requirements are referenced in each digital certification to permit business transactions to take place electronically, which heretofore often only would take place after at least one party physically winds his way through a corporate bureaucracy. The certifier in constructing a certificate generates a special message that includes fields indentifying the public key which is being certified, and the name of the certifiee. In addition, the certificate constructed by the certifier includes the authority which is being granted including information which reflects issues of concern to the certifier such as, for example, the monetary limit for the certifiee and the level of trust which is granted to the certifiee. The certificate may also specify cosignature requirements which are being imposed upon the certifiee.

Public key/signature cryptosystem with enhanced digital signature certification
Application Number
Publication Number
Application Date
February 12, 1988
Publication Date
September 19, 1989
Addison M Fischer
60 14th Ave. South, Naples, 33942
Nixon & Vanderhye
H04L 9/00
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