# Sonic // Writeup
## Problem
*Gotta go fast*
*nc chal.tuctf.com 30100*
## Solution
On that problem there was differents ways to solve it. For example, you can send every plaintext for each shift key ( 0 -> 26 ).
Or you can decode the message with the same shift key and do it until you got the flag : 
```pythonfrom pwn import * import codecs
while True:
    conn = remote('chal.tuctf.com' , 30100)    full_message = str(conn.recv())[301:]
    LIST = list(full_message)
    search=0    while search < len(LIST):        if LIST[search] == '\n':            for i in range(30):                try:                    del LIST[search]                except:                     pass        search += 1     encoded_message = ''.join(LIST)    rot13_message = codecs.encode(str(encoded_message) , 'rot_13')    conn.sendline(str(rot13_message))    recv = conn.recv()
    if 'TUCTF' in recv:        print(recv)        break     conn.close()```
**FLAG**: `TUCTF{W04H_DUD3_S0_F4ST_S0N1C_4PPR0V3S}`