TOKYO -- Nippon Telegraph and Telephone has found a way to use laser-light reflection in data encryption, a discovery that could help fight increasingly complex cyberattacks.
Random number sequences consisting of 0 and 1 are essential components of cryptographic systems. They are normally generated from mathematical formulas, but the weakness of this method is that the sequence becomes predictable if an attacker figures out the algorithm being used.
In contrast, methods utilizing irregular physical phenomena can achieve a higher level of unpredictability. NTT has developed a system that can generate random numbers based on the irregular and complex oscillation in the output light of a semiconductor laser whose output light is reflected by a mirror and injected back into the laser.
Generated at speeds of 4 gigabits per second, the random numbers could be supplied to computers and servers to encrypt data. The Japanese telecommunications company hopes to bring the technology to market within a few years.
Thermal noise measurement is among the technologies currently employing phenomenon-based methods. But its processing rate is around 100 megabits per second at best, and thus not suitable for high-speed transmissions of large amounts of data.