fengyuxing168的专栏

Electronic Codebook Mode (ECB),Cipher Block Chaining Mode (CBC).Cipher Feedback Mode (CFB) Only blocks of j <= 64 bits are enciphered at a time. A small j requires more cycles through the encipherment algorithm per unit of plaintext and thus greater processing overhead. A plaintext block always produces the same ciphertext block for the same key and starting variable. Blocks cannot be rearranged. Each ciphertext block depends on the current and all preceding plaintext blocks. Different starting variables are used to prevent the same plaintext enciphering to the same ciphertext. The strength of this mode depends on the size of the key k (best if j == k). An error will affect the current and the following ciphertext blocks. Output Feedback Mode (OFB) Only blocks of j <= 64 bits are enciphered at a time. A small j requires more cycles through the encipherment algorithm per unit of plaintext and thus greater processing overhead. A plaintext block always produces the same ciphertext block for the same key and starting variable. Different starting variables are used to prevent the same plaintext enciphering to the same ciphertext. Absence of chaining makes this mode vulnerable to specific attacks. Different start variable values prevent the same plaintext enciphering to the same ciphertext, by producing different key streams. An error bit in the ciphertext causes only one bit to be in error in the deciphered plaintext. It is not self-synchronizing. Triple-DES ECB Mode Encrypt with key1, decrypt with key2 and encrypt with key3 again. As for ECB encryption but increases the key length to 168 bits. If all keys are the same it is equivalent to encrypting once with just one key. If the first and last key are the same, the key length is 112 bits. If all 3 keys are the same, this is effectively the same as normal ECB mode. Triple-DES CBC Mode Encrypt with key1, decrypt with key2 and then encrypt with key3. As for CBC encryption but increases the key length to 168 bits with the same restrictions as the Triple-DES ESB mode Our first example shows how to use the basic DES encryption routine, DES_ecb_encrypt(), to encrypt or decrypt a single 64-bit block of plaintext to electronic code book (ECB) mode. If the encrypt argument is DES_ENCRYPT, the input (plaintext) is encrypted into the output (ciphertext) using the specified key_schedule. If the encrypt argument is DES_DECRYPT, the input (ciphertext) is decrypted into the output (plaintext). Note that input and output may overlap. Read more: http://blog.fpmurphy.com/2010/04/openssl-des-api.html#ixzz1n2Qte3UG

三重DES、DES的两种工作模式：ECB和CBC

aes加密与des加密（包括三重des加密与cbc工作模式）

使用DES算法；可以指定使用DES、2DES或者3DES算法；可以对任意的文件进行加密和解密，加密后文件扩展名为.des，可以指定使用ECB,CBC,CFB,OFB,CTR的任意一种模式；

3des加解密算法， 3des加解密算法

des加解密，详细将des的各个功能详细的说明，代码注释完整规范

编写 C 程序实现 DES 加、解密： (1) 编程实现 基于自己的名字来构造一 DES 密钥； (2) 应用 (1) 获得的密钥将一副灰度 图 (BMP 格式 ) 进行加、解 密； (3) 应用 ECB 和 CBC 两种操作模式分别完成

含DES原理实现介绍、DES算法C、C++代码实现。