[19a-A302-1~10] 3.10 Optical quantum physics and technologies

[19a-A302-10] Secure Communications Using Secret Keys Generated from Noise

〇Tatsuya Tomaru¹ (1.Hitachi R&D)

Keywords:cryptography, communication, noise

Secret communications are possible if bit errors and the difference in receive performance between Bob and Eve exist. The communication protocol is assumed to consist of three stages of random-number transmission, secret-key generation, and encrypted message transmission. The random numbers transmitted are coded using a common key, forming the difference between Bob and Eve. The security is assured by that the amount of the secret keys is limited to that of bit errors. This protocol allows to place a noise source inside a transmitter, and therefore, the channel is arbitrary. Using this property, we built prototype equipment that can operate only with it being connected to a LAN.