Quantum cryptography, or quantum key distribution (QKD), is one of the latest solutions to prevent hacking of sensitive data. As computers grow more sophisticated, we need more sophisticated encryption methods to prevent data from being hacked. QKD has been theorised for almost three decades but is a relatively recent phenomenon in terms of usage.

Recently, we have also seen the introduction of DIQKD, or device-independent quantum key distribution. DIQKD removes the potential for keys being passed to hackers, thereby reducing even further the potential risk of data being hacked. An overview of quantum cryptography and how it works can be found in the PDF attachment to this post.

Domen Zavrl has a broad interest in most things relating to finance and the economy and has taken Stanford courses in cryptography. Developments such as DIQKD are therefore of interest to Mr Zavrl.

Exchanging Quantum Mechanical Keys

Quantum mechanical keys can be exchanged using any one of a variety of methods. Entangled quantum systems may be employed, or light signals can be sent through a transmitter to a receiver. During entanglement, laser pulses are used to stimulate each atom, causing them to release a photon or light particle. The term ‘entanglement’ refers to the relationship between the spin of each atom with its own emitted photon. Once the particles have been transmitted to the receiver, atomic quantum memory entanglement can be read through the combined measurement of the photons.

A definition of what quantum means in computing can be seen in the embedded short video.

Detecting Hacking

One of the key factors that makes quantum cryptography so secure is that, if a hacker does manage to ‘disturb’ any data being sent, the receiver will immediately know about the attempt and will therefore be able to request the data be sent again with new encryption, rather than opening the current file or program. Hackers cannot just ‘see’ data being sent in this way – they must also measure the photons in the same way as the receiver. However, by doing this, they alter the message so the receiver will know immediately that someone is trying to intercept it. Receiving and transmitting devices need to be calibrated. When a hacker calibrates their own device to try and measure the photons, they change the nature of those photons in a way that can be easily detected.

The Rise of Cybercrime

Cybercrime is on the rise, increasing the necessity for developing new methods of cryptography to keep data safe online and when being communicated between two or more parties. Today, cybercrime affects around 80% of all businesses globally. As computers become more sophisticated, so do the skills and software available to hackers. Ransomware is the most common type of cyberattack, accounting for more than half of all cybercrimes. The most targeted databases are those containing healthcare information, as these are essential to many businesses and the data is often sensitive. Social media is also often used as a tool by hackers to compromise sensitive data or spread viruses and malicious software such as malware.

Some of the most common types of hacking currently in use are listed in the infographic attachment.

Quantum Cryptography Vs. Other Cryptography

While it appears that quantum cryptography has the power to make hacking obsolete, current technology prevents it from being practical for widespread use. Most quantum computers have not yet been optimised for QKD or DIQKD, and quantum computers are not yet widely available. While current methods of cryptography have an almost infinite radius, quantum cryptography is still in its infancy and can only practically be used between devices less than 10 miles apart.