The “Change Rate” describes fluctuations between two subsequent data securities. At a total amount of data of 10 Gigabyte, it lies around 100 to 200 Megabyte. Thus, the change rate is highly relevant for the compression and deduplication rate. In the worst case, all data blocks may be new originals. If the change rate were zero, the data might would be compressed by the factor 5. Four processes of data security needed to be effected in order to achieve a deduplication rate of 20:1. In case of a 10% change of the total data, a data compression by the factor 2 would be possible. 1,825 data securities would be needed in order to achieve a deduplication rate of 20:1.