The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Mar. 23, 2004
Filed:
Jun. 06, 2000
Huijie Robert Deng, Singapore, SG;
Yong Dong Wu, Singapore, SG;
Kent Ridge Digital Labs, Singapore, SG;
Abstract
A method, apparatus and a computer program product are described for copy protecting encrypted documents in a client-server system using an unsecured communication channel. The client-server system has clients and a server for storing encrypted documents. Encrypted documents e(K , M) are received by a client from the server. Communications on a transmission channel between the client and the server are then authenticated. Such communications also include electronic payments initiated by a user using the client. Upon authenticating or payment, an encrypted document can then be decrypted. After decrypting, the unencrypted document is displayed but prevented from storage at any client unless re-encrypted using a host specific key K associated with the client to thereby provide a re-encrypted document.