Patent ID: 7434058

Claim:
A method for generating a plurality of signatures over a document, the method comprising: extracting content from the document; normalizing the extracted content; generating the plurality of signatures using the normalized content; and tokenizing the normalized content prior to generating the plurality of signatures; wherein tokenizing the normalized content comprises creating an ordered list of tokens by converting each delimited item in the normalized content into a token; wherein generating the plurality of signatures comprises: i) selecting M consecutive tokens from the ordered list of tokens, M being a positive integer; ii) selecting N special tokens from the M consecutive tokens, N being a positive integer not greater than M; iii) generating a signature by calculating a hash over the N special tokens; iv) skipping ahead P tokens from the first of the M consecutive tokens, P being a positive integer; and v) repeating i), ii), iii), and iv) until the plurality of signatures have been generated.