CQC LogoCambridge Quantum (CQ), together with the Inter-American Development Bank (IDB) and the Monterrey Institute of Technology (TEC de Monterrey), published a paper describing the implementation of a quantum-safe blockchain, which was successfully demonstrated on the LACChain network and secured using CQ’s IronBridge quantum key generation platform.

Defending the blockchain against the threat of quantum computing required two enhancements to be made. Firstly, the blockchain was updated to use quantum-safe cryptographic algorithms, rather than vulnerable algorithms (such as ECDSA) that will be broken by quantum computers in as little as 5-10 years.

Secondly, the keys signing the blockchain transactions had to be completely unpredictable to present-day attackers as well as quantum-powered adversaries, otherwise fraudulent transactions would occur. This second step was achieved using CQ’s IronBridge quantum key generation platform – the only source of provably perfect and unpredictable cryptographic keys in the world.

It was possible to add these defences to the blockchain without making changes to the underlying blockchain engine (in this case, Ethereum). This was an important requirement for the IDB and also serves to demonstrate how easily quantum-safe technology integrates with existing infrastructure. Because of this, the project defines a blueprint for securing any blockchain deployment against the threats posed by quantum computers.

In addition to the technical details provided in the papers released by IDB (and mirrored on the ArXiv pre-print library), CQ will be hosting a webinar explaining how the technology proves the cryptographic keys are perfectly random and completely unpredictable to any attacker.


Founded in 2014, CQC is a global leader in quantum software and quantum algorithms that help our clients get the best out of existing and developing quantum computers. Over the past several years, our team has grown to 70 + accomplished scientists focused on creating the best quantum software and enabling systems in the world.

Our technologies help the world’s most innovative chemical, energy, financial and material science companies to harness the transformative impact of quantum computing.