Patent ID: 7574446

Claim:
A computer implemented method for converting a document character string into a numerical string representation, said document character string comprising a plurality of characters chosen from a group consisting of numbers, letters and punctuation, said method comprising: converting each of said plurality of characters to a plurality of corresponding first document equivalent characters; converting each of said plurality of corresponding first document equivalent characters to a plurality of corresponding second document equivalent characters by adding a constant to each of said first document equivalent characters; grouping a number of said second document equivalent characters into a document string representation, each document string representation having a predetermined number of second document equivalent characters; storing said document string representation in memory; electronically receiving a document identification string and operand, said document identification string comprising a plurality of document identification characters chosen from said group consisting of numbers, letters and punctuation; converting each of said plurality of document identification characters to a plurality of corresponding first document identification equivalent characters; converting each of said plurality of corresponding first document identification equivalent characters to a plurality of corresponding second document identification equivalent characters; grouping a number of said second document identification equivalent characters into a document identification string representation; storing said document identification string representation in said memory; comparing said document identification string representation to said document string representation based upon said operand; and in response to said operand and said comparison, electronically returning results of said comparison.