Quantum Key Distribution (QKD)

Quantum Key Distribution (QKD) is a secure communication technique that uses quantum mechanical concepts to construct a cryptographic protocol. It allows two people to generate a shared, randomly generated secret key that is only known to them. With this key, communications may be encrypted and decrypted. Since quantum key distribution is the most well-known example of a quantum cryptographic problem, it should not be mistaken for quantum cryptography. Instead of using mathematics to secure the data, QKD employs a quantum system that depends on fundamental principles of nature. This sets it apart from traditional key distribution.

What is Quantum Key Distribution (QKD)?

Quantum Key Distribution (QKD), A protected communication technique for sharing encryption keys. It exchanges cryptographic keys in a way that is verifiable and ensures security by using characteristics of quantum physics. Using QKD, two parties may generate and exchange a key for encrypting and decrypting communications. To be more precise, QKD is the process of sharing the key between participants.

Purpose of Quantum Key Distribution (QKD)

• To mollify the threat posed by the rapid advancements in Quantum Computing to the security of data being conveyed by many vital sectors across existing communication networks Quantum Key Distribution is needed.
• The technique might help several small and medium-sized businesses and start-ups in the quantum information space.
• It will make it possible for security services to design a proper quantum communication network with a backbone made of domestic technology.
• The way data is transported by photons is primarily responsible for the encryption’s unbreakability.
• A photon is impossible to replicate exactly, and each measurement effort will cause it to fluctuate. This implies that whoever tries to intercept the data will be caught.

Types of Quantum Key Distribution (QKD)

Below are two types of Quantum Key Distribution

• Entanglement-based protocols: Protocols based on entanglement centre on quantum states, where two items are coupled to generate a single quantum state. According to the idea of entanglement, measuring one entity therefore influences the other. The other parties involved will be aware if an eavesdropper gains access to a previously trusted node and makes any modifications.
• Prepare-and-measure protocols: The goal of prepare-and-measure procedures is to measure unidentified quantum states. They may be used to identify possible data interceptions as well as instances of eavesdropping.

How Quantum Key Distribution (QKD) Works?

The process involves the following steps:

• Several light particles, or photons, are sent between parties via fibre optic cables in order for Quantum Key Distribution to function.
• The photons are transmitted in a stream of ones and zeros, with each photon having a random quantum state.
• A photon passes via a beam splitter on its way to the receiving end, which compels it to choose a random path into a photon collector.
• The sender receives information from the receiver about the photon sequence that was transmitted, which they compare with the photon sequence that the emitter would have sent.
• A certain bit sequence is all that remains after photons in the incorrect beam collector are eliminated.
• During an error repair phase and other post-processing procedures, any mistakes and data leaks are eliminated.

Quantum Key Distribution (QKD) Attack Methods

• QKD appears secure in principle, security might be jeopardised by shoddy QKD implementations. Real-world applications have shown methods for breaking into QKD systems.
• An eavesdropper backdoor was intended to be created via the phase remapping exploit. The attack exploits the requirement for one party member to permit signals to enter and depart their device.
• The photon number splitting attack is an additional attack technique. A perfect scenario would allow one user to communicate with another user by sending one photon at a time.
• Coherent attacks are those that are deemed to demonstrate the security of a QKD system in the scenario when the eavesdropper possesses infinite processing capacity..

Benifits of Quantum Key Distribution (QKD)

Below are some benifits of Quantum Key Distribution

• QKD system may be utilised for more secure key management of several military cryptography systems in an integrated Cypher Policy Committee (CPC) framework in India.
• Security services will be able to create a suitable quantum communication network with a homegrown technological backbone thanks to it.
• The technique might help a number of small and medium-sized businesses and start-ups in the quantum information space.
• It is anticipated to define standards and develop rules pertaining to crypto technology.

Challenges of Quantum Key Distribution (QKD)

Below are some challenges of Quantum Key Distribution

• Establishing a classically authenticated communication route is necessary for quantum key distribution. This indicates that there was already enough security established because one of the involved users transferred a symmetric key in the first place.
• Putting in place the perfect infrastructure for QKD is challenging. In principle, it is completely safe, but in reality, security flaws are caused by flaws in instruments like single photon detectors.
• The distance that may be covered by terrestrial quantum key distribution (QKD) is limited by optical losses that occur during signal transmission through fibre and repeaters.
• Low cost and resilience are essential characteristics combined with excellent performance for QKD systems to be deployed in real-world applications. Many directions are being investigated at the moment.

Conclusion

In this article we have learned about Quantum Key Distribution (QKD). Quantum key distribution (QKD) is a secure communication technique that uses quantum mechanical concepts to construct a cryptographic protocol.In theory, QKD seems secure nonetheless, poor QKD implementations might compromise security. Techniques for breaching QKD systems have been shown by real-world applications.

Frequently Asked Questions on Quantum Key Distribution – FAQs

What problem does QKD solve?

Quantum Key Distribution (QKD) is a technique to address the issue of cryptography requiring the sharing of secret keys between remote Alices and Bobs.

What is the secure key rate of QKD?

The calculated secure key rates for 40 and 60 km of fibres are 446 and 166 kbit/s, respectively.

Which QKD protocol is best?

The Quantum Key Distribution protocol (QKD) and the most popular and useful QKD protocol is BB84.

Is QKD symmetric?

Using the principles of quantum physics, Quantum Key Distribution (QKD) creates a safe symmetric encryption key at two different sites.