Cambridge Researchers Devise New Blockchain Impervious Even to Quantum Computers

The superior power of quantum computing poses a threat to blockchain technology and the cryptocurrency segment. However, Cambridge Quantum, the quantum software leader in the UK, might prevent that from happening.

Cambridge Quantum has recently released a new study and its partners from the Inter-American Development Bank (IDB) and the Monterrey Institute of Technology (TEC de Monterrey). In the new report, now available in the preprint repository arXiv, researchers demonstrate a new blockchain technology that can supposedly resist attacks even from a quantum computer.

The new blockchain technology is detailed in the report "Quantum-resistance in blockchain networks," which describes the solution built on the LACChain network.

The Importance of Blockchain in Today's World

According to IBM, a blockchain is a shared, immutable digital ledger tracks all transactions and assets. It is mostly used for managing cryptocurrency, a digital medium of exchange that does not require a central bank to manage all of it. For example, the largest cryptocurrency in existence today, Bitcoin, uses blockchain technology so that no single person or entity would control all of them or that all users share ownership and control of the system.

As a type of database, it stores information in storage units known as blocks which are "chained" together. Whenever a new data enters this "ledger," a new block holds the data and is chained to the previous block, arranged in chronological order.

While they were originally thought to offer absolute security, there have been cases where blockchain technology has been hacked. In 2019, an attacker managed to hijack and gain control of the Etherium classic network, rewriting its transaction history and making it possible to spend cryptocurrency previously spent - known as double-spending. Media outlets, such as Forbes, came to identify the attack as the 51% Hack.

As more powerful devices come in the form of a quantum computer, the risk of attacks on blockchain networks also increases.

Resolving Inherent Weaknesses in Blockchain Technology

In their report, Cambridge Quantum reports finding four potential threat areas for blockchain networks: communication across network nodes and maintaining the integrity of digitally signed transactions. These threat areas are based on cryptography - or encrypting and decrypting data - and these processes are vulnerable to quantum computer attacks and need to be improved to keep up.

It led Cambridge Quantum researchers to develop a new post-quantum cryptography layer that offers an additional protection layer for networks, particularly against quantum computer attacks. The new blockchain solution was implemented on the LACChain Besu blockchain network, also based on Etherium technology.

"While certain quantum algorithms allow for breaches of digital security protocols, luckily we also have others we can use to strengthen our data protection capabilities," explains Salvador E. Venegas-Andraca, a professor-researchers and the Director Quantum Information Processing Group of Tecnologico de Monterey.

"LACChain blockchain was an ideal target for keys generated by our IronBridge platform," explains Duncan Jones, Cambridge Quantum's Head of Quantum Cybersecurity. "Only keys generated from certified quantum entropy can be resistant to the threat of quantum computing."