Inside The Race To Build QUANTUM-SECURE NETWORKS

If quantum communication becomes mainstream, our entire approach to digital security could change.

- DR SHAMIM HAQUE MONDAL serves in the Physics Division of the State Forensic Science Laboratory, Kolkata

We handle enormous volumes of information every day. Beyond the data flowing through internet banking, e-commerce, technology, industry, and governance, we constantly exchange personal messages on platforms such as WhatsApp and Facebook. In many ways, the internet has become a vast marketplace of information. Strengthening the security of that information is essential, and this forms the basis of network security.

Satellites anchor much of this communication infrastructure. If an unwanted third party infiltrates a satellite-based system, the accuracy and reliability of the information become uncertain. To understand the risk, it is necessary to examine how the telecommunication system operates and where its vulnerabilities lie.

This telecommunication system is based on a classical computer system, and network security is ensured by the Caesar cipher mechanism, a substitution encryption technique that shifts each letter in a message by a fixed number of positions. To illustrate, suppose Bimal, from one end of a field, sends a message to Rahim, who is at the other end. Rahim is the only person who knows the code that unlocks the encrypted original message.