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:
Nov. 16, 1999
Filed:
Mar. 31, 1997
Chung Nan Chang, Los Altos, CA (US);
Other;
Abstract
A first of two cryptographic units establish a cryptographic key 'K' by initially selecting a first quantity 'A', and computes second and third quantities 'B'=.PHI..sub.1 (A) and 'C'=.PHI..sub.2 (A). It must be mathematically impossible to compute A from B and the function .PHI..sub.1. The first unit then transmits B to the other cryptographic unit, and retains C. The second unit selects a fourth quantity 'D' and computes fifth and sixth quantities 'E'=.PHI..sub.3 (D) and 'F'=.PHI..sub.4 (D). It must be mathematically impossible to compute D from E and the function .PHI..sub.3. Upon receiving B, the second unit uses a fifth mathematical function '.PSI..sub.2 ' to compute the key 'K'=.PSI..sub.2 (F, B)=.PSI..sub.2 (.PHI..sub.4 {D}, .PHI..sub.1 {A}). Analogously, upon receiving E the first unit uses a sixth mathematical function .PSI..sub.1 to compute the key 'K'=.PSI..sub.1 (C, E)=.PSI..sub.1 (.PHI..sub.2 {A},.PHI..sub.3 {D})=.PSI..sub.2 (.PHI..sub.4 {D},.PHI..sub.1 {A}).