2020 | BJDCTF | Crypto

编码与调制

解题思路

• 给了一串密文 2559659965656A9A65656996696965A6695669A9695A699569666A5A6A6569666A59695A69AA696569666AA6 和一张提示图片
  
• 图片里是 01 串，不管怎么说先把密文按十六进制转换成二进制字符串吧！

  0010010101011001011001011001100101100101011001010110101010011010011001010110010101101001100101100110100101101001011001011010011001101001010101100110100110101001011010010101101001101001100101010110100101100110011010100101101001101010011001010110100101100110011010100101100101101001010110100110100110101010011010010110010101101001011001100110101010100110
  

• 接着，是图片里最明显的 Manchester 编码的解码。有点奇怪，有一位没解出来？(ΦˋωˊΦ)问题不大，反正只有两种情况，要么是 0，要么是 1

  ?1000010010010100100010001111011010001000110100101100110010011010110000101101110011000110110100001100101011100110111010001100101011100100110001101101111011001000110010101111101
  

• 当第一位填 0 时，转换成十六进制再对应到 ASCII 码可得 Flag：BJD{DifManchestercode}

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最后更新: 2021年5月17日 09:59:55

Contributors: YanhuiJessica
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