Abstract: A data compressor for a lossless data compression system includes a hardware aware encoder and a key signal processor. The hardware aware encoder encodes a data value signal into a key signal according to a key assignment formed by determining a number of data values of a value space in which each data value comprises a plurality of bits, determining a size of the key to encode the number of data values of the value space, grouping the data values into a plurality of groups based on a fewest number of bit differences between data values in each group, and assigning fragments of the key based on a fewest number of bits that can differentiate groups based on remaining bits of the data values. The key signal processor has an output adapted to be coupled to a medium for providing a representation of the key signal to the output.