A group of Japanese firms said Monday it had launched the country's first study into quantum cryptography in a bid to enhance the security of stock trading.

The joint study, commenced the same day by Toshiba Corp., NEC Corp. and Nomura Holdings Inc. among others, comes amid increasing threats from cyberattacks on financial institutions.

Quantum cryptography, in theory, is considered to be impossible for third parties to crack, the group said. The companies expect to put the technology into use in stock trading within several years.

In the joint research, they will connect a cryptographic device developed by Toshiba to a trading system at Nomura Securities Co., the brokerage unit of Nomura Holdings, and test run encryption using virtual customer details and trading data.

The simulations, conducted with a help from the National Institute of Information and Communications Technology, will look into the ability to encrypt numerous orders without delay even when millions are made simultaneously, they said. It will also check if there is any impact on the system when operations stretch for days.