Method and system for protection of digital information
US5978482A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Aug 21, 1995 |
| Grant date | Nov 2, 1999 |
| Priority date | — |
| Expiry date | Aug 21, 2015 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04L2209/60
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
An information processing system including an encryption processing logic module and a decryption processing logic module for enabling the encryption of digital information to be decrypted with a decryption key K. The encryption processing module includes logic for encrypting the digital information, distributing the digital information and authorizing a user to decrypt the information. The decryption processing module includes logic for the user to communicate a user number n.sub.i to receive an authorization number a.sub.i (a.sub.i being calculated as equal to ((K.sym.n.sub.i) raised to the power of (1/n.sub.i ' mod .phi. from the authorization logic in the encryption processing module and extrication logic for extricating the decryption key. The user number n.sub.i uniquely identifies, and is valuable to, the user, so valuable in fact that the user would be unwilling to publically disclose it. The extrication logic operates on a digital signet pair (a.sub.i, n.sub.i) consisting of the authorization number and user number, to extract K (K being calculated as equal to ((a.sub.i raised to the power of n.sub.i ') mod N.sym.n.sub.i)). The decryption logic then uses K to make the cont…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.