🚀 go-pugleaf

Another question, gentlemen. Suppose someone, the feds or whoever, hace 
an encrypted disk that they want to crack, but they don't know what 
cipher was used. How can they find out. Are there programs that will 
analyze it and make this determination based on the way certain ciphers 
cipher?
Can anyone define pre and post whitening and differential cryptanalysis, 
please?
Someone stated that with a mass DES chip machine using brute force to 
attack the DES, that the mode doesn't matter. Why even use it then? 
Again, thanks in advance!