For data encoded with an encoding scheme, a data compression technique utilizes encoding scheme values as compression indexing values where the encoding scheme values are part of the encoding scheme, but are not used to encode the data. In an implementation, a data compression dictionary is generated and indexed with the unused encoding scheme values. In an eight-bit encoding scheme, for example, the data is compressed from each letter and/or number being represented with eight bits down to complete words, numbers, and/or combinations of words and numbers being represented with only two bytes.