Information security is of great importance nowadays. This is related to the widespread use of new technologies in the development of long-distance communications and the use of increasingly “faster” signals. Information security can be considered in many areas of information processing, including wireless systems and wired systems that are based on electronic devices. Each of such devices is a source of electromagnetic disturbances but may also be sensitive to such disturbances. This Special Issue titled “Wireless Communication: Applications, Security, and Reliability” covers a broad spectrum of information security related to cybersecurity, cryptography, and electromagnetic protection. In each case, the information protection solutions used must keep up with the development of technologies used in information processing. The broad thematic area of this Special Issue was intended to encourage scientists and researchers to present their research results and the goals that this research was intended to serve. At the same time, it could allow for the exchange of knowledge and experience gained during the work on information security.