One of the main problems of the modern world is information security. In the future, data confidentiality will depend on cryptosystems that can withstand adversaries with unrestricted computing power. Since everyone now has access to a wide range of new algorithms and powerful computers, even our digital foes. The frequency of computer abuse incidents has increased with the use of computer communications networks technologies. The majority of organizations are under pressure to safeguard their assets as a result of these incidents. Most of the time, digital networks would deploy modern cryptosystems that protect integrity, confidentiality, and authenticity of the data that are being transmitted within the network. Also, current modern cryptosystems based on mathematical models introduce two important parameters in the security of any cryptography techniques, refresh rate of key and key expansion ratio. Both these securities parameters have identified because of the security holes that were discovered due to the advancement made related to computing powers of technologies. Correspondingly, efforts have been taken to lay a new foundation of cryptographic science in computer communications networks. One result of those efforts was the technology of quantum cryptography, security for which relies on principles of quantum mechanics. This chapter will dwell on how quantum cryptography works and is related to one step towards the improvement of cybersecurity.