Elementary Quantum Key Distribution Study of BB84 and E91 Protocols
Bhavesh B. Prajapati · International Journal of Scientific Research in Computer Science Engineering and Information Technology · 2018
Quantum Key Distribution (QKD) is a ground-breaking solution to secure communication that uses fundamental quantum mechanics principles to allow for the exchange of cryptographic keys with provable security. BB84 and E91, two of the first and most significant QKD systems, presented two different approaches to using quantum characteristics to prevent eavesdropping and maintain confidentiality. A brief literature review of these two fundamental protocols is presented in this paper. Bennett and Brassard created the BB84 protocol in 1984. It uses polarized photons and detects interception using the uncertainty principle. On the other hand, Bell's theorem and entangled photon pairs are used in the E91 protocol, which was first presented by Ekert in 1991, to guarantee the integrity of the shared key. Each protocol's theoretical foundations, methods of implementation, and relative benefits has been explored in addition to how they have influenced contemporary quantum cryptography systems. This paper attempts to give a basic understanding of QKD and its early advancements by examining the similarities and differences between BB84 and E91.