Communication is an activity which involves several parties (multi-party). The parties in these activities exchange information with each other.

Communication activities must have at least two participants. In the background, its main purpose is always to exchange information. It always reflects the sender’s intention.

The following simple and straightforward figure can characterize communication:

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In the beginning, the information is stored in a physical medium. The sender (person) converts it to be transferred via the communication channel. This process is called encryption.

We always have to take into consideration that the communication channel always has ’noise’, so our message will change its original meaning. Or a hacker or any kind of third-party participant who knows the encoding process can interfere and simply replace or just delete our message.

In order to prevent these scenarios people use the so-called //cryptographic// and //digital signature// procedures. The converter receives the data (on the side of the receiver) and reconverts it so that the receiver can understand the meaning of the message. It may repair the damage which can occur during the transmission process, and can verify the sender’s identity by using digital signatures.

If the transfer was successful the data can be stored on a physical storage medium.