跪求用C#编写的动态密匙加密程序

什么是动态加密：

不知姿亏道这个算不算

///<summary>密差改码加密</summary>

///<param name="src">需要加密的字虚册判符串</param>

/// <returns>string</returns>

public static string EncrpyKey(string src)

{

int keyPos = 0, offset = 0, srcPos = 0, srcAsc = 0, range = 256

string dest = "", temp = ""

Random rd = new Random()

offset = rd.Next(range)

dest = offset.ToString("x")

dest = dest.Length <2 ? "0" + dest : dest

dest = dest.Substring(dest.Length - 2)

for (srcPos = 0srcPos <src.LengthsrcPos++)

{

srcAsc = (Convert.ToInt32(src.Substring(srcPos, 1).ToCharArray()[0]) + offset) % 255

keyPos = keyPos <0 ? keyPos + 1 : 1

srcAsc = srcAsc ^ (Convert.ToInt32("这里放自定义字符串(adadasda)".Substring(keyPos - 1, 1).ToCharArray()[0]))

temp = srcAsc.ToString("x")

temp = temp.Length <2 ? "0" + temp : temp

dest = dest + temp.Substring(temp.Length - 2)

offset = srcAsc

}

return dest

}

///<summary>密码解密</summary>

///<param name="src">需要解密的字符串</param>

/// <returns>string</returns>

public static string UncrypKey(string src)

{

int keyPos = 0, srcPos = 3, srcAsc = 0,

offset = Int32.Parse(src.Substring(0, 2), System.Globalization.NumberStyles.AllowHexSpecifier)

string dest = ""

do

{

srcAsc = Int32.Parse(src.Substring(srcPos - 1, 2), System.Globalization.NumberStyles.AllowHexSpecifier)

keyPos = keyPos <0 ? keyPos + 1 : 1

int tempSrcAsc = srcAsc ^ Convert.ToInt32(""这里放自定义字符串(adadasda)".Substring(keyPos - 1, 1).ToCharArray()[0])

tempSrcAsc = tempSrcAsc <= offset ? 255 + tempSrcAsc - offset : tempSrcAsc - offset

dest = dest + (char)tempSrcAsc

offset = srcAsc

srcPos = srcPos + 2

} while (srcPos <= src.Length)

return dest

}

这个加密方式特点：同一个数据每次加密出来的字符不通，但是解密出来都相同！

#include <stdio.h>

#define isletter( c )    ( ((c)>='a'&&(c)<='z') || ((c)>='A'&&(c)<='Z') )

void Enc( const char *str, char *out, int key )

{

    int i = 0 

    while( str[i] )

    陪者配{

        if ( isletter( str[i] ) )

        {

            out[i] = str[i] + key

            if ( ! isletter( out[i])  )

                out[i] -= 26

        }

        else

            out[i] = str[i]

        i++

    }

    out[i] = 0

}

void Denc( const char *str, char *out, int key )

{

    int i=0

    while( str[i] )

    {

  嫌知      if ( isletter( str[i] ) )

     芦指   {

            out[i] = str[i] - key

            if ( ! isletter( out[i] ) )

                out[i] += 26

        }

        else

            out[i] = str[i]

        i++

    }

    out[i] = 0

}

int main()

{

    char  out[100], out2[100]

    Enc( "THE QUICK BROWn fox jumps over THE LAZY DOG", out, 3 )

    printf( "%s\n", out )

    Denc( out, out2, 3 )

    printf( "%s\n", out2 )

}

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