Abstract: Methods for identifying potentially sensitive information and protecting such potentially sensitive information include scanning systems that collect and/or disseminate such information. Without limitation, systems collect and/or disseminate personal identification numbers (e.g., personal identification numbers, tax identification numbers, etc.), such as merchant systems, bank systems, healthcare systems, and the like, that collect, use, or disseminate sensitive information may be scanned to identify sequences of data that are likely to be sensitive, and may take actions to protect such sequences of data. Scanning and protection systems are also disclosed.

Abstract: A data string that includes potentially sensitive information, such as an account number for a payment card, may be evaluated using a delimiter search to provide an increased level of confidence that the data string encodes the sensitive information of interest. A delimiter search may include an evaluation of the bytes adjacent to the beginning and end of the data to determine whether or not those bytes have values that correspond to the values of known delimiters. A data string that is not surrounded by known delimiters may be disregarded (i.e., considered not to comprise sensitive information of interest), while a data string that is surrounded by known delimiters may warrant further evaluation.

Abstract: A data string that includes potentially sensitive information, such as an account number for a payment card, may be evaluated to determine whether or not any portion of the data string encodes a known identifier of sensitive information, such as a known bank identification number (BIN). A fixed number of bytes of the data string may be analyzed using a trie algorithm, in which the value of a first byte is compared with the value of a corresponding first character of the known identifier. A second byte is then compared with a set of values of corresponding second characters, which accompany the first character of the known identifier. Then the value of a third byte of the data string is compared with a set of values of corresponding third values, which accompany the first and second characters of the known identifier. The use of a trie algorithm decreases the length of the search process by several orders of magnitude.

Abstract: 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.