HSBC Holdings Plc will become the first British bank to test an advanced data-security system being run by UK telecom giant BT Group Plc, Amazon.com Inc.’s AWS cloud and Japan’s Toshiba Corp.

So-called quantum key distribution is a type of cyber defense that financial institutions think could help protect trillions of dollars of transactions from increasingly sophisticated hackers in the future.

While it won’t be a standalone cybersecurity method, it may be an important part of the defense strategy for companies like HSBC as the technology develops. Later generations of quantum computers could slice through the mathematics modern encryption is based on, so a separate and critical part of preparing for what’s known as “Q-Day” is finding new encryption methods.

“As technology develops and current methods begin to be defeated, we have to make sure we have the most up-to-date robust encryption and security standards,” HSBC Chief Executive Officer for Europe Colin Bell said in an interview. “Ultimately it becomes a ‘when’ question rather than an ‘if’ question — and hence why we are very pleased to take part in a trial like this.”

Participating in the trial involves the bank installing equipment to send test data 62 kilometers (38.5 miles) between its headquarters in London’s Canary Wharf financial district and a data center in the neighboring county Berkshire. HSBC said the trial will help it better analyze threats and work out how to protect data.

Quantum key distribution is a way two remote parties can agree a shared secret key to encrypt and decrypt data. Forms of it have been in development for years and are in large part reliant on the properties of quantum physics.

HSBC isn’t the first bank to consider quantum key distribution as a potential long-term security method; JPMorgan Chase said last year it had “demonstrated the ability of the newly developed QKD network to instantly detect and defend against eavesdroppers” as part of a system also involving Toshiba.