Ranking and de-ranking data strings

Abstract

This document describes example methods, devices, and computing systems to rank a data string into a ranking value, and de-rank a second value representative of a variation of the ranking value (e.g., cipher value) into a second data string (e.g., cipher string), using a tree data-structure. The tree data-structure defines a domain of values representative of all variations of a set of characters that satisfy a format within which the data string is defined. The ranking value is identified with respect to a first offset value calculated for individual characters of the data string relative to the domain of values of the tree data-structure. The second value is de-ranked into a second data string of individual characters identified with respect to a second offset value calculated in the domain of values of the tree data-structure relative to the second value. This method may be performed using the tree data-structure to rank a data string into a ranking value, and de-rank a cipher version of the ranking value into a cipher string. Similarly, this method may be performed to accomplish the reverse process of ranking a cipher string to a ranking value, and de-ranking a decrypted version of the ranking value to a decrypted data string.