Description of the Intermediate Value Known Answer Test

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The test encrypts one plaintext with a variable number of rounds.

In ECB encryption mode, the output PTi is the output after the 

initial key addition and i rounds (a round ends with a key

addition). 

As explained in the documentation, in ECB decryption mode 

there are several definitions of a `round' possible. In order

to make visual inspection more intuitive, we output the

intermediate values that correspond with the output of the

encryption mode. 

These values might actually not occur in a practical decryption,

especially in an optimised implementation, where various operations

of different rounds are interchanged.

This explains also why the Java and the C code output different

files for this test.