Az információtechnológia természettörvényei

Information theory consists of the theoretical limits of the economical and secure solutions of certain information technology tasks and the encoding rules approaching these limits. These tasks may involve the compression and protection of information during information transfer and storage. There are two types of compression. One is loss-free compression the other involves loss. Protection of information may mean protection against noisy information transmission (error correcting coding), data protection (encryption), access protection or authentication (digital signature). Of these information security tasks the lecture describes in detail error correcting coding. According to the law of error correcting coding, data transfer can both be economical and secure, i.e. there exists a maximum level of channel utilisation: channel capacity. The most important characteristic of information is that it is random; therefore the laws of information theory use and further develop the law of large numbers.