How quantum cryptography could bolster secure online communications
AUTHOR : Kouta Ibukuro

In today’s world of modern communications, many people are concerned about their privacy – but quantum technologies could help to safeguard sensitive online conversations and transactions against eavesdroppers.

A sequence of random numbers is used in cryptography to securely deliver a person’s passwords, credit card numbers, or bank account details online. However, the current way to generate random numbers is often based on an algorithm, making it possible to break the cryptography.

In our project, we are developing a fully physical hardware-based random number generator based on a silicon single-electron semiconductor device, known as a transistor. It could then be integrated into a microprocessor to operate smartphones or laptops.

Once fully developed and slotted into electronic consumer devices, the chances of a person’s most private information being overheard could be significantly reduced.

A phenomenon we use for the random number generator, called random telegraph signal or popcorn noise, is observed in many fields, such as physics, chemistry and electronics. It is considered to be switching events between two possible states for a quantum – such as an atom, electron, or molecule – the behaviour of which cannot be treated as an object around us.

However, a good explanation is missing to describe why the same noise occurs in different contexts. Understanding its mechanism may also have a huge scientific impact.