Basis32

• Category: Crypto
• 100 Points
• Solved by the JCTF Team

Description

Solution

Super secret Shabak's message, cool!

it's look like someone substitute the BASE32 letters with the Hebrew Aleph-Beit by order

א -> A ב -> B etc...

let's try to decode it

# coding=utf-8
import base64

def replace_heb_letter_to_base32_letters(c):
    if ord(c) >= ord(u'א') and ord(c) - ord(u'א') < 26:
        c = chr(ord(c) - ord(u'א') + ord(u'A'))
    elif c == u'ת':  # special case for the letter 'ת'
        c = u'2'
    return c

data = u'טייצעשדומםךהרץסעזאשדא6תמם53ץ6עך7ךץקזטשכעמםתזג3ףהכ5הז65ת7טינקזשיףזיןפג3דחם5שזע5דטםץןץמ33עםםשקת==='

data = u''.join([replace_heb_letter_to_base32_letters(c) for c in data])
print base64.b32decode(data)

The flag: BSidesTLV2020{Now_I_Understand_How_Base32_Algorithm_Works}