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. 10, 2011
Filed:
Aug. 01, 2006
Jung-hong Kao, Los Altos, CA (US);
Mete Yilmaz, Palo Alto, CA (US);
Jungfu Tsao, San Jose, CA (US);
Shoujung Jimmy Tsao, Fremont, CA (US);
Mick Henniger, Buchanan Dam, TX (US);
Jung-Hong Kao, Los Altos, CA (US);
Mete Yilmaz, Palo Alto, CA (US);
Jungfu Tsao, San Jose, CA (US);
Shoujung Jimmy Tsao, Fremont, CA (US);
Mick Henniger, Buchanan Dam, TX (US);
Cisco Technology, Inc., San Jose, CA (US);
Abstract
Techniques are provided for generating a hash value for searching for substrings in a data stream without reading more than one element (e.g. one byte) at a time. According to one technique, a before a next element is added to an old hash value, the old hash value is circularly shifted one or more bits. The first original element is shifted a number of bits and XOR'ed against the old hash value. The next element is added to the old hash value. In one embodiment, an entry value is retrieved for each element from an index table and the XOR and shift operations are performed on the entry values. According to another technique, each Linear Feedback Shift Register (LFSR) of a plurality of LFSRs read in one element at a time beginning at different offsets. Each LFSR uses the same state machine. The result of reading a number of elements into an LFSR is used as the hash value.