1. A method for string signature scanning, comprising: processing one or more signatures into one or more formats including selecting one or more fingerprints for each fixed-size signature or each of one or more fixed-size signature substrings of each a variable-size signature and constructing one or more search data structures for the one or more fingerprints associated with the one or more signatures and one or more follow-on search data structures, each successive fingerprint of a particular fixed-size signature or signature substring having a first basic unit in a scanning direction that is shifted one or more units from the previous fingerprint of the particular fixed-size signature or signature substrings such that the number of fingerprints for the particular fixed-size signature or signature substrings is equal to a step size for a signature scanning operation and the particular fixed-size signature or signature substring is identifiable at any location within any string fields to be scanned, where each fingerprint includes one or more fragments of a particular fixed-size signature or signature substring, the one or more fragments having particular locations anywhere within the particular fixed-size signature or signature substring; receiving a particular string field comprising a string of data values; identifying any signatures included in the particular string field including scanning the particular string field for the one or more fingerprints associated with the one or more signatures with either a zero or non-zero false positive rate using the one or more search data structures for the one or more fingerprints for each scan step size and searching the particular string field for the one or more signatures associated with one or more identified fingerprints using the one or more follow-on search data structures at the locations where the one or more identified fingerprints are found; and outputting any identified signatures in the particular string field.