We propose and numerically demonstrate an
ultrafast secure key distribution based-on random DNA coding
and the chaos synchronization in two identical electro-optic
oscillators (EO) with common injection. High-quality
synchronization between the responses of EOs with extremely
sensitivity to the mismatching of time delay and phase bias is
observed. It is noted that the random DNA coding and the delay
DNA-XOR in the post-processing can greatly amplify the
randomness of the synchronized sequences acquired by
symmetrically dual-threshold sampling the correlated physical
entropies, and enhance the security of key distribution by
providing additional encryption. According to our study, high
rate key distribution of over 10 Gb/s can be fulfilled with a good
consistency, which can be used for the commercial
communication networks.