“One of the most singular characteristics of the art of deciphering is the strong conviction possessed by every person, even moderately acquainted with it, that he is able to construct a cipher which nobody else can decipher. Shannon’s development was also based on Harry Nyquist’s work, which determined the sampling rate as a function of frequency necessary to reconstruct an analog signal using a set of discrete samples. Entropy comes from the Greek word for transformation and, in physics, is related to the logarithm of the ratio between the final and initial temperature of a system or to the ratio of the heat variation and the temperature of the same system. The concept of information transmission is associated with the existence of a communication channel that links the source and destination of the message. This can imply the occurrence of transmission errors, caused by the probabilistic nature of the channel.