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:
Dec. 11, 2001
Filed:
Feb. 13, 1998
Philip R. Wiser, Redwood City, CA (US);
Andrew R. Cherenson, Los Altos, CA (US);
Tze-Yee Szeto, Santa Cruz, CA (US);
Liquid Audio, Inc., Redwood City, CA (US);
Abstract
A device securely decrypts and writes an encrypted digital file to a local recordable storage medium. The device uses two decryption engines. The first decryption engine incrementally decrypts the encrypted digital file, which is then preprocessed and re-encrypted to form an intermediate file. The second decryption engine then incrementally decrypts the intermediate file and writes the decrypted results to a local recordable storage medium. Both decryption engines perform incremental decryption, such that substantially less than all of the digital file is in decrypted form at any instant. A device in accordance with a second embodiment includes a single decryption engine. The encrypted digital file includes individually encrypted portions, and the decryption engine incrementally decrypts the encrypted portions. These portions are buffered for subsequent writing to the recordable storage medium, but substantially less than all of the individually encrypted portions are stored in decrypted form at any instant.