BJDCTF2020/BUUCTF-CRYPTO:编码与调制

题目下载

密文：2559659965656A9A65656996696965A6695669A9695A699569666A5A6A6569666A59695A69AA696569666AA6

考察了曼切斯特编码。先将hex转成bin，在一步步替换‘10’为‘1’，‘01’为‘0’ 。

strr = bin(0x2559659965656A9A65656996696965A6695669A9695A699569666A5A6A6569666A59695A69AA696569666AA6)[2:]
step = 2
str2 = [strr[i:i+step] for i in range(0,len(strr),step)]
flag = []
final = ""
for i in str2:
    flag.append(i)
for i in flag:
    if(i=="10"):
        final += "1"
    if(i=="01"):
        final += "0"
print(hex(int(final,2)))