Crunchfish Digital Cash AB has received an International Preliminary Report on Patentability (IPRP) in Chapter II of the Patent Cooperation Treaty (PCT) for a key Digital Cash patent application PCT/SE2023/050294 with a focus on making Digital Cash quantum-safe, indicating that all claims 1 - 45 are deemed patentable. This patent makes Crunchfish Digital Cash future-proof and secured for attacks by quantum computing and extends Crunchfish extensive patent portfolio within the Digital Cash business area. Crunchfish has applied for a patent that makes Digital Cash resistant to attacks by quantum computing, keeping payment information secure even after large-scale quantum computers has been built.

The advent of large-scale quantum computing offers great promise to science and society but brings also significant threats to the global information infrastructure. Public-key Infrastructure, widely used on the internet, relies upon cryptography that is believed to be secure given the computational power currently available. However, popular cryptographic schemes, including RSA and Elliptic Curve Cryptography, will be easily broken by a quantum computer.

This will rapidly accelerate the obsolescence of currently deployed security systems and will have dramatic impacts on any industry, including payments, where information needs to be kept secure. The innovation is based on combining two different data integrity schemes and offers a new paradigm for offline payments that addresses the challenges which can be expected in the era of quantum computing. A two-step process is applied.

Payments are first negotiated offline by short-range data communication using a quantum-secure cryptographic key as a shared secret. Subsequently, payment settlement by broadband data communication is secured by signing the settlement request with another quantum secure cryptographic key. With quantum computing, all information that is transmitted on public channels is vulnerable to eavesdropping.

Encrypted data can also be stored for later decryption once quantum computing becomes available. Bitcoin is one example where previously made transactions are accessible by anyone and puts a substantial amount of Bitcoin at risk. Even if large-scale quantum computers are still a few years into the future, preparations must be made now, as the timing when technical innovation leapfrogs is hard to predict.

The patent has priority from a Swedish patent application filed in March 2022. The next step is to enter the phase of nationalization by September 2024 when Crunchfish must decide which markets to protect this important innovation. A patent would be valid until March 2042, 20 years from the original filing date.