Inventor · Northborough, MA, US

Charles W. Kaufman

78Patents
30h-index
109Co-inventors
91Inventor score

Filing activity: Apr 28, 1988 → Sep 12, 2022

Most-cited inventions

PatentTitleAreaCited byStatus
US5224163A Method for delegating authorization from one entity to another through the use of session encryption keys Electricity 350 Expired
US5666415A Method and apparatus for cryptographic authentication Electricity 348 Expired
US5491752A System for increasing the difficulty of password guessing attacks in a distributed authentication scheme employing authentication tokens Physics 249 Expired
US5220604A Method for performing group exclusion in hierarchical group structures Emerging Cross-Sectional Technologies 196 Expired
US5497421A Method and apparatus for protecting the confidentiality of passwords in a distributed data processing system Physics 193 Expired
US5261002A Method of issuance and revocation of certificates of authenticity used in public key networks and other systems Electricity 171 Expired
US6061799A Removable media for password based authentication in a distributed system Electricity 168 Expired
US5418854A Method and apparatus for protecting the confidentiality of passwords in a distributed data processing system Physics 152 Expired
US5500860A Router using multiple hop redirect messages to enable bridge like data forwarding Electricity 149 Expired
US5787169A Method and apparatus for controlling access to encrypted data files in a computer system Physics 132 Expired
US5081678A Method for utilizing an encrypted key as a key identifier in a data packet in a computer network Electricity 120 Expired
US5018137A Transparent load sharing for parallel networks Electricity 104 Expired
US5796830A Interoperable cryptographic key recovery system Electricity 96 Expired
US5764772A Differential work factor cryptography method and system Electricity 91 Expired
US6052469A Interoperable cryptographic key recovery system with verification by comparison Electricity 90 Expired
US5574860A Method of neighbor discovery over a multiaccess nonbroadcast medium Electricity 83 Expired
US5128926A Updating link state information in networks Electricity 77 Expired
US6178508A System for controlling access to encrypted data files by a plurality of users Physics 66 Expired
US5664099A Method and apparatus for establishing a protected channel between a user and a computer system Physics 65 Expired
US6094721A Method and apparatus for password based authentication in a distributed system Electricity 64 Expired
US5070528A Generic encryption technique for communication networks Electricity 63 Expired
US5086469A Encryption with selective disclosure of protocol identifiers Electricity 63 Expired
US5483598A Message encryption using a hash function Electricity 59 Expired
US5815573A Cryptographic key recovery system Electricity 54 Expired
US5796740A Router using multiple hop redirect messages to enable bridge like data forwarding Electricity 50 Expired

Source: USPTO / EPO open patent data. Inventor disambiguation is heuristic; counts are objective bibliographic measures.