Data Backup Digest

With modern cryptocurrency growing in popularity and engineers coming up with new, innovative ways to use blockchain technology, many are still left searching for an unbreakable level of blockchain security; and they may have found it with quantum key distribution (QKD) and quantum cryptography.

What is Quantum Key Distribution?

To put it simply, QKD provides a secure method of exchanging encryption keys between shared parties. Since modern encryption is easily surpassed if you have the encryption key, it’s important to keep these keys as secure as possible and beyond the reach of hackers and other malicious users.

It’s important to understand that QKD simply refers to a new method of distributing keys in a secure fashion. The encryption key itself, as well as data that is being encrypted in the first place, is still generated through ordinary means.

Bolstering the Blockchain

Under conventional key distribution, a public key is used to process highly complicated mathematical calculations. Since these algorithms can’t be defeated by modern, consumer-grade computers, this conventional method provides a level of security that is good enough by most standards.

However, security that is considered “good enough” still isn’t strong enough for the most sensitive data. And that’s exactly where quantum key distribution, or QKD, comes in.

With QKD, data is transmitted via light particles through fiber optic cables. These light particles, also known as photons, then comprise a series of ones and zeros known as qubits. As expected, qubits are equivalent to ordinary bits in the binary system.

Once it reaches its destination, the photons travel through a beam splitter before making their way to the final photon collector, where they are re-assembled. This complete process provides a highly efficient and highly secure means of encrypting data.

Currently, there are several different types of QKD. However, two primary forms are used – both of which are useful when trying to detect cases of potential eavesdropping.

• Prepare-and-measure
• Entanglement-based

In addition, there are currently several different QKD protocols available for use, including:

• BB84
• Decoy state
• E91
• KMB09
• Silberhorn

Unfortunately, QKD still faces many challenges. For starters, it’s difficult – and costly – to integrate next-gen QKD systems into modern IT infrastructure. The total distance that photons are able to travel will also limit the use of QKD.

Technical Limitations

There are also some technical imitations of QKD that need to be overcome before it can be used to secure data on the government level. According to the U.S. National Security Agency (NSA), neither QKD nor quantum cryptography are recommended for this kind of sensitive data – at least until the remaining technical limitations are overcome.

• QKD increases the risk of denial-of-service (DoS) attacks
• Since the tolerance for error is much smaller than other forms of security, it’s incredibly difficult to validate QKD systems
• QKD systems result in higher IT infrastructure costs, including long-term maintenance fee
• Much of the data confidentiality provided via QKD can be achieved with quantum-resistant cryptographic systems, which are less expensive to implement on a large scale

If these limitations are overcome, we might see the NSA using quantum cryptography and QKD in the near future. Until then, however, it remains a relatively unexplored territory.