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:
Oct. 15, 1991
Filed:
May. 03, 1990
Thomas I Elmer, Sunnyvale, CA (US);
Tuan T Nguyen, Milpitas, CA (US);
Rung-Pan Lin, San Jose, CA (US);
National Semiconductor Corp., Santa Clara, CA (US);
Abstract
An encryption method is taught which chooses certain bytes of data, stored in a particular on-chip memory, as encryption keys. These chosen bytes are used to encrypt themselves, and all of the remaining data in the above mentioned particular memory. The chosen bytes do not have values specifically assigned for encryption, they are merely chosen, according to a rule, from the body of data to be encrypted. When this technique is implemented, each byte of data, stored in the mentioned memory, is combined (for example using an exclusive NOR gate) with one of the designated encryption key bytes prior to disclosure. The user is not required to provide, program, or safeguard a set of key bytes separately. Additionally, no silicon area is wasted in storing such bytes. An intruder would need certain pieces of the original data in order to decipher the results of this encryption technique. Additionally, this technique degrades gracefully. The keys are chosen such that encrypted data does not have a single common dependency. Thus, in the event a single key is discovered, only a very small portion of the encrypted data will be disclosed.
Data source: USPTO (United States Patent and Trademark Office) public patent records. Weekly synchronization. How IDiyas builds this profile