Tags: python crypto 

Rating:

* Browser Try visit http://124.71.145.165:9999/, Can not open
* So, Try nc, Success, return some mesage, a menu
* Try In Python console:
```
>>>a=[101.675707, 108.104373, 99.44578, 119.753137, 103.825127, 123.795102, 113.940518, 112.825059, 119.928117, 100.072409, 110.66016, 112.893151, 119.509267, 120.783183, 99.383149, 118.112178, 118.08295, 98.985339, 101.026835, 97.877011, 101.01231, 93.011009, 111.948902, 115.130663, 116.7992, 92.919232, 101.367718, 103.783665, 100.882058, 99.945761, 95.911013, 114.825181, 98.854674, 110.959773, 116.05761, 112.636004, 95.454217, 108.25799, 96.539226, 108.040692, 113.843402, 105.545774, 123.853208, 96.72447, 97.942793, 124.169743, 124.625649]
>>>[chr(int(round(i))) for i in a]
['f', 'l', 'c', 'x', 'h', '|', 'r', 'q', 'x', 'd', 'o', 'q', 'x', 'y', 'c', 'v', 'v', 'c', 'e', 'b', 'e', ']', 'p', 's', 'u', ']', 'e', 'h', 'e', 'd', '`', 's', 'c', 'o', 't', 'q', '_', 'l', 'a', 'l', 'r', 'j', '|', 'a', 'b', '|', '}']
```
* what the "RANDOM" Noise, emmm:
```
from pwn import *

def readDat():
p.sendlineafter(":", "2", timeout=3)
ret = p.recvuntil("\n", timeout=1)
ret = ret.replace(",\n","")
return eval("["+ret+"]")

MAX_C=1000
buf=readDat()
L=len(buf)
C=1
for k in range(0,MAX_C):
a=readDat()
#print(a)
if len(a)!=L:
continue
C = C+1
for i in range(0,L):
buf[i] += a[i]

for i in range(0,L):
buf[i] = int(round(buf[i] / C))

buf_arr = [chr(i) for i in buf]
#print("COUNT="+str(C))
print("".join(buf_arr))

```

Original writeup (https://ctftime.org/task/12939/writeup/).