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:
May. 16, 1995
Filed:
Jul. 06, 1993
David A Cane, Sudbury, MA (US);
David S Hirschman, Sharon, MA (US);
Phoenix Technologies, Ltd., Norwood, MA (US);
Abstract
A method and system for protecting computer program distribution within a broadcast medium involves encrypting at least a portion of the computer program S.sub.i using an encryption scheme keyed to both an encryption key SK.sub.i and a program identifier i. Each decryption device (PCDD) also has an associated identifier j. Two tables are generated and stored in a memory device: a first table, including correlations between the encryption key SK.sub.i and the program identifier i; and a second table, including correlations between the password key PK.sub.j and the hardware identifier j. A password P.sub.ij is generated based on both the encryption key SK.sub.i and a password key PK.sub.i is retrieved from these tables. The password P.sub.ij is transmitted to the user for subsequent use in decrypting the subject software program contained on the medium.