2.1-2.4

One of the interesting things from the reading was the vigenere cipher which shifts a variable amount since it is a clever modification of the shift cipher. The first method for attacking the cipher is interesting since finding the key length seems somewhat incredible since it just involves counting coincidences. Finding the key was expected since it just analyzed letter frequencies. One thing that was not quite explained was how a combination of several ciphers could be solved. For example if a vigenere cipher was applied to a random substition cipher or the other way around, would it need new methods for an attack?