Potentially sensitive information (e.g., account numbers for payment cards, etc.) may be identified from data by use of an “interval scanning” technique, in which a string of data is evaluated in intervals. When a system employs an interval scanning technique, data is evaluated by analyzing bytes of data in periodic sequence (e.g., every thirteenth byte, etc.), while the bytes between the analyzed bytes are initially ignored. If the value of an analyzed byte corresponds to a character of interest (e.g., a decimal numeral or numeric digit (i.e., a character having a value that corresponds to a base-ten, or Arabic, number, 0, 1, 2, 3, 4, 5, 6, 7, 8, or 9), etc.), that byte is identified as a “base byte,” from which a more focused evaluation (e.g., a byte-by-byte analysis, or sequential analysis, etc.) may then commence.