basic-mod1 - PicoCTF2022

100 points

AUTHOR: WILL HONG

Description

We found this weird message being passed around on the servers, we think we have a working decrpytion scheme.Download the message here.Take each number mod 37 and map it to the following character set: 0-25 is the alphabet (uppercase), 26-35 are the decimal digits, and 36 is an underscore.Wrap your decrypted message in the picoCTF flag format (i.e. picoCTF{decrypted_message})

message

91 322 57 124 40 406 272 147 239 285 353 272 77 110 296 262 299 323 255 337 150 102

Answer

import string

alphabet=string.ascii_lowercase+string.digits+'_'

text='91 322 57 124 40 406 272 147 239 285 353 272 77 110 296 262 299 323 255 337 150 102'
tab_text=text.split()
#print(tab_text)
for digit in tab_text:
    digit=int(digit)%37
    
    print(alphabet[digit], end="")
    
#print(alphabet)

Po zastosowaniu takiego kodu otrzymałem r0und_n_r0und_add17ec2. Co było poprawną odpowiedzią :)

picoCTF{r0und_n_r0und_add17ec2}