已知明文攻击

结果表明，S1和S2都易受已知明文攻击，而S3不能正确解密。

The results show that both S1 and S2 are vulnerable to the known plaintext attacks and S3 can not decrypt correctly .

实现了对该方案的选择明文攻击、选择密文攻击和已知明文攻击。

We found that this scheme cannot resist chosen plaintext attack , cho-sen ciphertext attack and known plaintext attack .

对基于算术编码的一个数据加密算法的已知明文攻击

An attack with known plaintexts to an encryption algorithm based on arithmetic coding

双随机相位加密系统的已知明文攻击

Known-plaintext attack on double phase encoding encryption technique

对一个混沌伪随机序列发生器的已知明文攻击

Known-plaintext Attack on Chaotic Pseudo-random Sequence Generator

这种结合了自适应算法的加密模式，使算法的扩散性能增强，能很好的抵抗选择明文攻击和已知明文攻击。

The improved encryption mode has a good diffusion and it can resist Chosen Plaintext Attack and Known Plaintext Attack .

据此利用已知明文攻击，对该算法提出了分割攻击方案，并分析了该攻击方案的成功率和计算复杂性。

So the paper proposes divide - and - conquer attack with known plaintexts and analyses its success probability and complexity .

这种方法基于传统混沌加密算法，利用混沌系统对初始条件的敏感依赖性，在图像加密过程中引入一个辅助密钥，可有效抵抗已知明文攻击。

Using the high sensitivity to the initial value of the chaos system , an assistant key is imported based on conventional chaotic encryption algorithm .

实验表明该算法具有较强的抵御穷举攻击、统计攻击、已知明文攻击能力，因此，算法具有较高的安全性。

The experiment results showed that the algorithm has stronger resistance for the exhaustion , count attack , the known-plaintext attack , and it is of high security .

通过引入辅助密钥，实现了一次一密意义下的身份认证，能够抵抗已知明文攻击，提高了系统安全性。

The assistant key was presented in the system , can improve the encryption security by the " one key one time " process which can resist plain-text attack .

提出了一种改进的安全信道建立算法，新的算法能够承受已知明文攻击，同时还提高了加、解密运算的效率。

A improved algorithm that builds security channel is provided , the new algorithm not only against known-plaintext attack , but also enhance efficiency of operation for encryption and decryption .

混沌信号产生便捷并且具有很好的随机特性，将混沌序列用于图象信息加密有很好的加密效果，但现有的一些基于混沌的图象加密方式难以抵抗已知明文攻击。

Because chaotic signals are easy to generate and have good random property , the application of chaotic sequence in image encryption has good effect , but those image encryption scheme existed can 't resist plain-text attack .

第二，单一的依赖伪随机序列作为密钥不能抵抗已知明文攻击。第三，存在较多无效密钥。为克服这些潜在缺点，本文对图像的混沌置乱算法进行了研究。

Secondly , the solely dependence of pseudo random sequences on the keys , which leads to the adversary to get the information by known-plaintext attack . Thirdly , there exists a number of invalid keys and weak keys .

安全性分析表明，这2个方案的安全性均是基于椭圆曲线上的离散对数难题，且具有只有指定的接收者才能恢复原消息、抗已知明文攻击和消息密钥不能重复使用等性质。

The analysis shows the security of both schemes are based on the problem of elliptic curve discrete logarithm , only appointment receiver can recover original message , anti-known plaintext attack and the message key can not be used repeatedly .

这是由于线性加密系统中明文、密文、密钥之间的函数关系相对较简单，无法有效抵抗选择明文攻击、已知明文攻击等常见攻击。

The reason is that the functional relationship among plaintext , ciphertext and key is comparatively simple in a linear encryption system , which makes the encryption system potentially insecure against some common attacks such as chosen - and known-plaintext attacks .

由于此类算法扩散性能不强，易导致选择明文攻击和已知明文攻击，且置乱过程过于简单，本文提出了一种可行的攻击方法。③根据自适应算法的原理，对算法进行了改进。

Because the characteristic of diffusion is too poor to resist Chosen Plaintext Attack and Known Plaintext Attack , a feasible attack process is proposed . Next , according to the advantages of self-adaptive algorithm , an improved algorithm based on self-adaptive algorithm is presented .

该算法引入小波变换，可以有效地克服一些混沌加密算法不能抵御已知/选择明文攻击的缺陷。

The chaotic image encryption is resilient to known / chosen plaintext attack because of the adoption of wavelet transformation .

最后给出了对该类方案的已知明文的同态攻击方法，弥补了该类方案理论分析上的不足。

Homeostasis attack of this kind of scheme is also proposed with known plaintext , all of these could make up the shortcoming of theory analysis .

分析及仿真结果表明，上述两个算法可以有效地克服一些混沌加密算法不能抵御已知/选择明文攻击的缺陷。（3）提出了两个混沌图像加密算法的应用方案。

The analysis and simulation results show that above two algorithms can resist known / chosen image attack . ( 3 ) The application schemes of above two chaos-based encryption algorithms are given .

给出的实验结果表明，算法克服了现有的一些混沌加密算法的缺陷，可以有效地抵御一类已知/选择明文攻击，增强了加密图像的安全性。

The corresponding results show that the improved chaotic image encryption algorithm overcomes the original disadvantages , and is resilient to one known / chosen plaintext attack because of the adoption of wavelet transformation .

在对现有一类典型图像混沌加密算法的分析基础上，提出了一种改进的混沌图像加密算法，该算法引入小波变换，可以有效地克服一些混沌加密算法不能抵御已知／选择明文攻击的缺陷。

Based on the analysis of a typical chaotic image encryption , an improved algorithm is proposed . The chaotic image encryption is resilient to known / chosen plaintext attack because of the adoption of wavelet transformation .

实验仿真结果表明，两种算法都能达到很好的加密效果，都能抵抗一定程度的穷举攻击、统计攻击、已知（选择）明文攻击、差分攻击。

Simulation results and analysis show that the proposed two cryptosystems have good encryption performance and can resist brute-force attack , statistical attack , known-plaintext attack , chosen-plaintext attack and differential attack in some extent .