We introduce some basic concepts concerning two fundamental aspects of information theory, namely, the error control coding and the cryptography. The information is first “encoded” in a way so that the receiver can “decode” the transmitted message, i.e., the receiver can detect and correct the transmission errors. The overall reliability of a communication system depends on how appropriate is the chosen “data transmission scheme”. The core idea due to Richard W. HammingRichard W. Hamming (1915–1998) is to create redundancy in the transmitted message while encoding.