The book "Opportunistic Encryption" by Betascript Publishing provides a comprehensive introduction to the concept of opportunistic encryption (OE). This technique allows systems to attempt to encrypt the communication channel when connecting to another system, reverting to unencrypted communication in case of failure. The book explains how this method works and its areas of application, which do not require prior agreements between the involved systems. Although opportunistic encryption does not offer the highest level of security, as authentication can be challenging, it still represents a viable solution to facilitate the encryption of internet traffic and thereby enhance security online. The authors Lambert M. Surhone, Miriam T. Timpledon, and Susan F. Marseken provide valuable insights into the technique and its significance for IT security.