In embodiments of the present invention improved capabilities are described for scanning a data set for the presence of a target string. The data set may be received at a computing facility and cause a scanning program to execute. A first character pair in the data set may be identified where each character making up the first character pair is identified in a vector map. It may then be confirmed that the first character pair matches a positive indicated bitmask in a bitmap matrix, and verify that the position of the first character pair matches a position of a matching character pair in the target string. An action may be caused to be taken as a result of the verification.