1. A method operating on one or more network devices, comprising: receiving input data; selecting a candidate input matching data segment from within the input data by sliding a window over the input data and for each of a plurality of different locations of the sliding window determining a fitness function from a portion of the input data within the sliding window and further selecting a portion of the input data having a determined best fitness function value by performing a comparison between each of the determined fitness functions; determining a corresponding candidate store matching segment of data in a synchronized store based on an index determined from the selected candidate input matching data segment, the index being used to obtain a file identifier and offset that is then used to locate within the synchronized store the candidate store matching segment; selectively revising at least one boundary of the candidate input matching data segment by comparing data contiguous with the candidate store matching segment with data contiguous with the candidate input matching data segment to generate an input matching data segment of the input data; determining an encoded representation of the input matching data segment at least partly based on the synchronized store; and transmitting over a network a data structure that includes at least a portion of an unmatched portion of the data within the input data and the encoded representation.