The anomalies also suggest the product may be vulnerable to cryptanalytic attack. The first sixteen tests in the above table are taken from the DieHard tests that were developed under a grant from the National Science Foundation. You can read a description of the tests and download the tests from here. When the value of the measured parameter is outside the expected distribution, an implementation mistake is suspected. See the following sketch.
Ciphertext repetitions represent an inherent weakness in the basic encryption algorithm.
In general, the lower the repetitions factor, the better the scrambling of data and less available are repetitions to feed to the cryptanalysis for an analysis advantage. The entropy calculation is an important measure of predictability and organization. If entropy is low the data is well organized, and orderly. Higher entropy indicates a stronger level of obfuscation of data. The closer the observed cipher text is to random text, the more difficult it is to recover the original plain text.