Description: Cryptanalysis of an image encryption scheme based on a new total shuffling algorithm-Chaotic systems have been broadly exploited through the last two decades to build
encryption methods. Recently, two new image encryption schemes have been proposed,
where the encryption process involves a permutation operation and an XORlike
transformation of the shuffled pixels, which are controlled by three chaotic systems.
This paper discusses some defects of the schemes and how to break them with
a chosen-plaintext attack. Platform: |
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Author:xiaowang |
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Description: 本加密程序基于著名的TEA加密算法,密钥长度为128位,安全性高于DES算法(56位).
该算法安全、简洁、高效,加密解密速度极快,占用内存极少，非常适合于嵌入式系统
的加密解密，也能胜任大系统的安全性能要求。算法能防止常见的密码学攻击。
本程序中待加密的明文、加密生成的密文皆按64位数据分组进行加解密。
密钥长度128位，与AES、IDEA相当，从而确保足够的安全性。-The encryption program is based on the famous TEA encryption algorithm, key length 128 bits, safe in the DES algorithm (56). The algorithm safe, simple, efficient, fast encryption and decryption, occupy very little memory, very suitable for embedded systems encryption and decryption, also qualified for the safety of large-scale system performance requirements. Algorithm to prevent the common cryptographic attack. The procedure to be encrypted plaintext, encrypted ciphertext are carried out by a 64-bit data packet encryption and decryption. 128-bit key length, and AES, IDEA rather, to ensure adequate security. Platform: |
Size: 2048 |
Author:YCLIU |
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Description: 基于密码加密的暴力破解法。猜测密码长度，3-6位，并逐一尝试破解，找出正确密码。-Brute-force Search Attack on the Password-based Encryption
The program is divided into three parts: encryption, decryption and brute-force attack, which are the three methods in my class. In the brute-force attack method, use the given cipher text and the length of the password to try all possible passwords to encrypt the predefined plaintext and find the correct password. Platform: |
Size: 16384 |
Author:Will |
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Description: 随着网络带宽和计算机处理能力的高速增长, 数字
图像在当今社会的各个领域被广泛使用. 由于网络的开
放性, 涉及国家安全、商业利益和个人隐私的图像需要
进行加密, 以保护其安全. 将传统的加密标准, 如IDEA
和AES 直接应用到图像的加密上存在一定的缺陷. 因
为传统的加密算法主要为一维的数据流设计, 没有考虑
二维图像的特性, 如空间有序性、视觉冗余性、相关性等
等. 这使得传统加密算法在加密数据量较大的图像时要
耗费较长的时间.
与一般的二进制数据不同, 数字图像具有明显的空
间有序性, 因此可以通过改变这种有序性来设计快速的
图像加密算法. 改变有-Abstract: Recently, Chen etc. propo sed a no vel self adaptive image encryption algorithm. The analysis shows that it is vul
nerable to chosen plaintext attack. Then the original algorithm is revised based on self adaptive image encryptoin technique. The ex
periments show that the revised algorithm has better performance on both security and speed than two known algorithms.
Key words: cryptography image encryption self adaptive cryptanalysis1 Platform: |
Size: 6144 |
Author:wangc |
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Description: 对“一种超混沌图像加密算法的安全性分析及其改进”的选择明文攻击(1).pdf-On " a super chaotic image encryption algorithm analysis and improvement of safety," the chosen-plaintext attack (1). Pdf Platform: |
Size: 841728 |
Author:li |
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Description: A rainbow table is a precomputed table for reversing cryptographic hash functions, usually for cracking password hashes. Tables are usually used in recovering the plaintext password, up to a certain length consisting of a limited set of characters. It is a practical example of a space/time trade-off, using more computer processing time at the cost of less storage when calculating a hash on every attempt, or less processing time and more storage when compared to a simple lookup table with one entry per hash. Use of a key derivation function that employs a salt makes this attack infeasible. Platform: |
Size: 1248256 |
Author:moro |
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Description: 置换密码算法的原理是不改变明文字符，只将字符在明文中的排列顺序改变，从而实现明文信息的加密。置换密码也叫换位密码。
试编程实现矩阵换位密码。它的加密方法是将明文中的字母按照给定的顺序安排在一个矩阵中，然后用根据密钥提供的顺序重新组合矩阵中的字母，形成密文。例如，明文为attack begins at five，密钥为cipher，将明文按照每行6个字母的形式排在矩阵中，如下形式：
a t t a c k
b e g i n s
a t f i v e
根据密钥cipher中各字母在字母表中出现的先后顺序，给定一个置换：
根据上面的置换，将原有矩阵中的字母按照第1、4、5、3、2、6的顺序排列，则有下列形式：
a a c t t k
b i n g e s
a i v f t e
从而得到密文：aacttkbingesaivfte
解密过程类推。
-The principle of permutation cipher algorithm is to change the order of characters in plaintext without changing the plaintext characters, so as to realize the encryption of plaintext information. Permutation cipher is also called transposition cipher.
Programming to achieve matrix transposition password. Its encryption method is that the letters in the plaintext are arranged in a matrix according to a given order, and then the letters in the matrix are re assembled in the order provided by the key to form a ciphertext. For example, the plaintext is attack begins at five, the key is cipher, and the plaintext is placed in the matrix in the form of 6 letters per row, as follows:
A, t, t, a, C, K
B, e, G, I, N, s
A, t, F, I, V, e
According to the order in which the letters in the key cipher appear in the alphabet, a permutation is given:
According to the above permutation, the letters in the original matrix are arranged in the order of first, fourth, fifth, 3, 2 and 6, and the follo Platform: |
Size: 1024 |
Author:1 |
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Search - plaintext attack