DES加密算法实验报告

1、州科技学院实验报告学生：涛学号：1220126117 指导教师：滔 学书 1220126114实验地点：计算机学院大楼东309 实验时间：2015-04-20一、 实验室名称：软件实验室二、实验项目名称：DES加解密算法实现三、实验学时：4学时四、实验原理：DES算法由加密、子密钥和解密的生成三部分组成。现将DES算法介绍如下。1加密DES算法处理的数据对象是一组64比特的明文串。设该明文串为m=m1m2m64 (mi=0或1)。明文串经过64比特的密钥K来加密，最后生成长度为64比特的密文E。其加密过程图示如下：图2-1：DES算法加密过程对DES算法加密过程图示的说明如下：待加密的64比特

2、明文串m，经过IP置换（初始置换）后，得到的比特串的下标列表如下：表2-1：得到的比特串的下标列表IP58504234261810260524436282012462544638302214664564840322416857494133251791595143352719113615345372921135635547393123157该比特串被分为32位的L0和32位的R0两部分。R0子密钥K1(子密钥的生成将在后面讲)经过变换f(R0,K1)（f变换将在下面讲）输出32位的比特串f1,f1与L0做不进位的二进制加法运算。运算规则为：f1与L0做不进位的二进制加法运算后的结果赋给R1，R0

3、则原封不动的赋给L1。L1与R0又做与以上完全一样的运算，生成L2，R2 一共经过16次运算。最后生成R16和L16。其中R16为L15与f(R15,K16)做不进位二进制加法运算的结果，L16是R15的直接赋值。R16与L16合并成64位的比特串。值得注意的是R16一定要排在L16前面。R16与L16合并后成的比特串，经过置换IP-1（终结置换）后所得比特串的下标列表如下：表2-2：置换后所得比特串的下标列表IP-140848165624643239747155523633138646145422623037545135321612936444125220602835343115119592

4、734242105018582633141949175725经过置换IP-1后生成的比特串就是密文e。变换f(Ri-1,Ki):它的功能是将32比特的输入再转化为32比特的输出。其过程如图2-2所示：图2-2：将32比特的输入再转化为32比特的输出f变换说明：输入Ri-1(32比特)经过变换E（扩展置换E）后，膨胀为48比特。膨胀后的比特串的下标列表如下：表2-3：膨胀后的比特串的下标列表E:3212345456789891011121312131415161716171819202120212223242524252627282928293031321膨胀后的比特串分为8组，每组6比特。各组

5、经过各自的S盒后，又变为4比特(具体过程见后)，合并后又成为32比特。该32比特经过P变换（压缩置换P）后，其下标列表如下：表2-4：压缩置换P后的下标列表P:1672021291228171152326518311028241432273919133062211425经过P变换后输出的比特串才是32比特的f（Ri-1,Ki）.S盒的变换过程: 任取一S盒。见图2-3：图2-3在其输入b1,b2,b3,b4,b5,b6中，计算出x=b1*2+b6, y=b5+b4*2+b3*4+b2*8，再从Si表中查出x 行，y 列的值Sxy。将Sxy化为二进制，即得Si盒的输出。（S表如图2-4所示）图2

6、-4以上是DES算法加密原理五、实验目的：了解DES加密算法与原理，掌握其基本应用。六、实验容：了解DES加密算法与原理，掌握其基本应用，利用java编程实现。七、实验器材（设备、元器件）：（1） PC（2） Windows 8.1系统平台（3） java程序开发环境。八、源代码：package WindowsDemo;publicclass DesUtil byte bytekey;public DesUtil(String strKey) this.bytekey = strKey.getBytes(); / 声明常量字节数组privatestaticfinalint IP = 58, 5

7、0, 42, 34, 26, 18, 10, 2, 60, 52, 44, 36, 28, 20, 12, 4, 62, 54, 46, 38, 30, 22, 14, 6, 64, 56, 48, 40, 32, 24, 16, 8, 57, 49, 41, 33, 25, 17, 9, 1, 59, 51, 43, 35, 27, 19, 11, 3, 61, 53, 45, 37, 29, 21, 13, 5, 63, 55, 47, 39, 31, 23, 15, 7 ; / 64privatestaticfinalint IP_1 = 40, 8, 48, 16, 56, 24, 6

8、4, 32, 39, 7, 47, 15, 55, 23, 63, 31, 38, 6, 46, 14, 54, 22, 62, 30, 37, 5, 45, 13, 53, 21, 61, 29, 36, 4, 44, 12, 52, 20, 60, 28, 35, 3, 43, 11, 51, 19, 59, 27, 34, 2, 42, 10, 50, 18, 58, 26, 33, 1, 41, 9, 49, 17, 57, 25 ; / 64privatestaticfinalint PC_1 = 57, 49, 41, 33, 25, 17, 9, 1, 58, 50, 42, 3

9、4, 26, 18, 10, 2, 59, 51, 43, 35, 27, 19, 11, 3, 60, 52, 44, 36, 63, 55, 47, 39, 31, 23, 15, 7, 62, 54, 46, 38, 30, 22, 14, 6, 61, 53, 45, 37, 29, 21, 13, 5, 28, 20, 12, 4 ; / 56privatestaticfinalint PC_2 = 14, 17, 11, 24, 1, 5, 3, 28, 15, 6, 21, 10, 23, 19, 12, 4, 26, 8, 16, 7, 27, 20, 13, 2, 41, 5

10、2, 31, 37, 47, 55, 30, 40, 51, 45, 33, 48, 44, 49, 39, 56, 34, 53, 46, 42, 50, 36, 29, 32 ; / 48privatestaticfinalint E = 32, 1, 2, 3, 4, 5, 4, 5, 6, 7, 8, 9, 8, 9, 10, 11, 12, 13, 12, 13, 14, 15, 16, 17, 16, 17, 18, 19, 20, 21, 20, 21, 22, 23, 24, 25, 24, 25, 26, 27, 28, 29, 28, 29, 30, 31, 32, 1 ;

11、 / 48privatestaticfinalint P = 16, 7, 20, 21, 29, 12, 28, 17, 1, 15, 23, 26, 5, 18, 31, 10, 2, 8, 24, 14, 32, 27, 3, 9, 19, 13, 30, 6, 22, 11, 4, 25 ; / 32privatestaticfinalint S_Box = /S-盒 / S_Box1 14, 4, 13, 1, 2, 15, 11, 8, 3, 10, 6, 12, 5, 9, 0, 7 , 0, 15, 7, 4, 14, 2, 13, 1, 10, 6, 12, 11, 9, 5

12、, 3, 8 , 4, 1, 14, 8, 13, 6, 2, 11, 15, 12, 9, 7, 3, 10, 5, 0 , 15, 12, 8, 2, 4, 9, 1, 7, 5, 11, 3, 14, 10, 0, 6, 13 , / S_Box2 15, 1, 8, 14, 6, 11, 3, 4, 9, 7, 2, 13, 12, 0, 5, 10 , 3, 13, 4, 7, 15, 2, 8, 14, 12, 0, 1, 10, 6, 9, 11, 5 , 0, 14, 7, 11, 10, 4, 13, 1, 5, 8, 12, 6, 9, 3, 2, 15 , 13, 8,

13、10, 1, 3, 15, 4, 2, 11, 6, 7, 12, 0, 5, 14, 9 , / S_Box3 10, 0, 9, 14, 6, 3, 15, 5, 1, 13, 12, 7, 11, 4, 2, 8 , 13, 7, 0, 9, 3, 4, 6, 10, 2, 8, 5, 14, 12, 11, 15, 1 , 13, 6, 4, 9, 8, 15, 3, 0, 11, 1, 2, 12, 5, 10, 14, 7 , 1, 10, 13, 0, 6, 9, 8, 7, 4, 15, 14, 3, 11, 5, 2, 12 , / S_Box4 7, 13, 14, 3,

14、0, 6, 9, 10, 1, 2, 8, 5, 11, 12, 4, 15 , 13, 8, 11, 5, 6, 15, 0, 3, 4, 7, 2, 12, 1, 10, 14, 9 , 10, 6, 9, 0, 12, 11, 7, 13, 15, 1, 3, 14, 5, 2, 8, 4 , 3, 15, 0, 6, 10, 1, 13, 8, 9, 4, 5, 11, 12, 7, 2, 14 , / S_Box5 2, 12, 4, 1, 7, 10, 11, 6, 8, 5, 3, 15, 13, 0, 14, 9 , 14, 11, 2, 12, 4, 7, 13, 1, 5,

15、 0, 15, 10, 3, 9, 8, 6 , 4, 2, 1, 11, 10, 13, 7, 8, 15, 9, 12, 5, 6, 3, 0, 14 , 11, 8, 12, 7, 1, 14, 2, 13, 6, 15, 0, 9, 10, 4, 5, 3 , / S_Box6 12, 1, 10, 15, 9, 2, 6, 8, 0, 13, 3, 4, 14, 7, 5, 11 , 10, 15, 4, 2, 7, 12, 9, 5, 6, 1, 13, 14, 0, 11, 3, 8 , 9, 14, 15, 5, 2, 8, 12, 3, 7, 0, 4, 10, 1, 13,

16、 11, 6 , 4, 3, 2, 12, 9, 5, 15, 10, 11, 14, 1, 7, 6, 0, 8, 13 , / S_Box7 4, 11, 2, 14, 15, 0, 8, 13, 3, 12, 9, 7, 5, 10, 6, 1 , 13, 0, 11, 7, 4, 9, 1, 10, 14, 3, 5, 12, 2, 15, 8, 6 , 1, 4, 11, 13, 12, 3, 7, 14, 10, 15, 6, 8, 0, 5, 9, 2 , 6, 11, 13, 8, 1, 4, 10, 7, 9, 5, 0, 15, 14, 2, 3, 12 , / S_Box

17、8 13, 2, 8, 4, 6, 15, 11, 1, 10, 9, 3, 14, 5, 0, 12, 7 , 1, 15, 13, 8, 10, 3, 7, 4, 12, 5, 6, 11, 0, 14, 9, 2 , 7, 11, 4, 1, 9, 12, 14, 2, 0, 6, 10, 13, 15, 3, 5, 8 , 2, 1, 14, 7, 4, 10, 8, 13, 15, 12, 9, 0, 3, 5, 6, 11 ;privatestaticfinalint LeftMove = 1, 1, 2, 2, 2, 2, 2, 2, 1, 2, 2, 2,2, 2, 2, 1

18、; / 左移位置列表privatebyte UnitDes(byte des_key, byte des_data, int flag) / 检测输入参数格式是否正确，错误直接返回空值（null）if (des_key.length != 8) | (des_data.length != 8)| (flag != 1) & (flag != 0) thrownew RuntimeException(Data Format Error !); int flags = flag;/ 二进制加密密钥int keydata = newint64;/ 二进制加密数据int encryptdata = n

19、ewint64; / 加密操作完成后的字节数组byte EncryptCode = newbyte8;/ 密钥初试化成二维数组int KeyArray = newint1648;/ 将密钥字节数组转换成二进制字节数组 keydata = ReadDataToBirnaryIntArray(des_key);/ 将加密数据字节数组转换成二进制字节数组 encryptdata = ReadDataToBirnaryIntArray(des_data);/ 初试化密钥为二维密钥数组 KeyInitialize(keydata, KeyArray); / 执行加密解密操作 EncryptCode =

20、Encrypt(encryptdata, flags, KeyArray);return EncryptCode; / 初试化密钥数组privatevoid KeyInitialize(int key, int keyarray) int i;int j;int K0 = newint56;/ 特别注意：xxxIPi-1等类似变换for (i = 0; i 56; i+) K0i = keyPC_1i - 1; / 密钥进行PC-1变换 for (i = 0; i 16; i+) LeftBitMove(K0, LeftMovei); / 特别注意：xxxIPi-1等类似变换for (j =

21、0; j 48; j+) keyarrayij = K0PC_2j - 1; / 生成子密钥keyarrayij / 执行加密解密操作privatebyte Encrypt(int timeData, int flag, int keyarray) int i;byte encrypt = newbyte8;int flags = flag;int M = newint64;int MIP_1 = newint64;/ 特别注意：xxxIPi-1等类似变换for (i = 0; i 64; i+) Mi = timeDataIPi - 1; / 明文IP变换 if (flags = 1) /

22、加密for (i = 0; i -1; i-) LoopF(M, i, flags, keyarray); for (i = 0; i 64; i+) MIP_1i = MIP_1i - 1; / 进行IP-1运算 GetEncryptResultOfByteArray(MIP_1, encrypt);/ 返回加密数据return encrypt; privateint ReadDataToBirnaryIntArray(byte intdata) int i;int j;/ 将数据转换为二进制数，存储到数组int IntDa = newint8;for (i = 0; i 8; i+) In

23、tDai = intdatai;if (IntDai 0) IntDai += 256; IntDai %= 256; int IntVa = newint64;for (i = 0; i 8; i+) for (j = 0; j 8; j+) IntVa(i * 8) + 7) - j = IntDai % 2; IntDai = IntDai / 2; return IntVa; privatevoid LeftBitMove(int k, int offset) int i;/ 循环移位操作函数int c0 = newint28;int d0 = newint28;int c1 = ne

24、wint28;int d1 = newint28;for (i = 0; i 28; i+) c0i = ki; d0i = ki + 28; if (offset = 1) for (i = 0; i 27; i+) / 循环左移一位 c1i = c0i + 1; d1i = d0i + 1; c127 = c00; d127 = d00; elseif (offset = 2) for (i = 0; i 26; i+) / 循环左移两位 c1i = c0i + 2; d1i = d0i + 2; c126 = c00; d126 = d00; c127 = c01; d127 = d01

25、; for (i = 0; i 28; i+) ki = c1i; ki + 28 = d1i; privatevoid LoopF(int M, int times, int flag, int keyarray) int i;int j;int L0 = newint32;int R0 = newint32;int L1 = newint32;int R1 = newint32;int RE = newint48;int S = newint86;int sBoxData = newint8;int sValue = newint32;int RP = newint32;for (i =

26、0; i 32; i+) L0i = Mi; / 明文左侧的初始化 R0i = Mi + 32; / 明文右侧的初始化 for (i = 0; i 48; i+) REi = R0Ei - 1; / 经过E变换扩充，由32位变为48位 REi = REi + keyarraytimesi; / 与KeyArraytimesi按位作不进位加法运算if (REi = 2) REi = 0; for (i = 0; i 8; i+) / 48位分成8组for (j = 0; j 6; j+) Sij = RE(i * 6) + j; / 下面经过S盒，得到8个数 sBoxDatai = S_Boxi

27、(Si0 1) + Si5(Si1 3) + (Si2 2) + (Si3 1) + Si4;/ 8个数变换输出二进制for (j = 0; j 4; j+) sValue(i * 4) + 3) - j = sBoxDatai % 2; sBoxDatai = sBoxDatai / 2; for (i = 0; i 32; i+) RPi = sValuePi - 1; / 经过P变换 L1i = R0i; / 右边移到左边 R1i = L0i + RPi;if (R1i = 2) R1i = 0; / 重新合成M，返回数组M/ 最后一次变换时，左右不进行互换。此处采用两次变换实现不变if

28、 (flag = 0) & (times = 0) | (flag = 1) & (times = 15) Mi = R1i; Mi + 32 = L1i; else Mi = L1i; Mi + 32 = R1i; privatevoid GetEncryptResultOfByteArray(int data, byte value) int i;int j; / 将存储64位二进制数据的数组中的数据转换为八个整数（byte）for (i = 0; i 8; i+) for (j = 0; j 8; j+) valuei += (data(i 3) + j (7 - j); for (i

29、= 0; i 128) valuei -= 255; privatebyte ByteDataFormat(byte data, int flag) int len = data.length;int padlen = 8 - (len % 8);int newlen = len + padlen;byte newdata = newbytenewlen; System.arraycopy(data, 0, newdata, 0, len);for (int i = len; i newlen; i+) newdatai = (byte) padlen;return newdata; publicbyte DesEncrypt(byte des_data, int flag) byte format_key = ByteDataFormat(bytekey, flag);byte format_data = ByteDataFormat(des_data, flag);int datalen = format_data.length;int unitcount = datalen / 8;byte result_data = newbytedatalen;for (int i = 0; i = 1) & (delete_len = 8) ? delete_