Functional Test And Key Space Based On CPRS Algorithm

Chaotic systems are widely applied for information safety for its wonderful characteristics of cryptography due to the randomness,irregular behavior and the sensitivity to initial conditions.However,the chaotic system has only one positive Lyapunov exponent which leads to the bad performance of safety security and anti-attack.Therefore,the study builds the CPRS system by using two identical improved one-way coupled ring map lattice(IOCRML)with active-passive decomposition(APD).The highlight of the CPRS hyper-chaotic system lies in the Logistic equation including multiple positive Lyapunov exponents and the chaotic data truncation that makes it impossible to be decrypted by the attacker for being unable to obtain the original chaos data.Firstly,the performance of system which is influenced the security and randomness and the effect of truncated bits is discussed in detail based on CPRS hyper-chaotic system according to the Matlab simulation.The general rule of the influence of parameter difference is obtained.The result indicates that the algorithm has a better security and good performance of randomness.It is difficult to achieve synchronization as long as the parameters have only minor changes between encryption system and decryption system due to CPRS hyper chaotic system is extremely sensitive to the change of the system parameter,resulting in plaintext cannot be accurately restored.Therefore,these parameters can be used as the key space parameters.As a sequence,we design the key space including an "S_Box"algorithm and three different valuing algorithms based on initial value,system parameter and coupling coefficient which turn out to be distributed uniformly and randomly.