时空混沌保密通信系统的微扰攻击法

Slight perturbation attack on spatiotemporal chaotic cryptosystem

研究了基于时空混沌的保密通信系统的安全性问题。此类系统在常数驱动下,高维的接收机系统将收敛至一维,使得系统对叠加于常数驱动上的微小扰动不敏感。基于此缺陷,提出了一种微扰攻击方法:选择一个常数驱动,使得系统被控制到均匀的目标态,然后在常数驱动上叠加一个微小的扰动,使得系统重新收敛后的状态与扰动前的目标态之间的距离保持在微小的范围内,使得系统取整取模的作用失效,暴露出系统的状态变量,从而可以用较小的计算代价获得密钥。

The security problems of spatiotemporally chaotic cryptosystem are studied. This kind of systems has the weakness that the high dimensional receiver degenerates to be one-dimensional under constant driving, therefore, is no more sensitive to the slight perturbation on the driving after convergence. Based on this weakness, a slight perturbatioin attack method is proposed： choosing a constant driving, thus the receiver systm degenerates to uniform object state; adding a slight perturbation to the constant driving, and making the distance between pre-perturbation state and post-perturbation state in a small extent. This attack disabled the effects of INT and MOD operations and exposed the state variables. The experimental results show that this method can successfully get the key to some precision with relatively small computation cost.