How 2FA Actually Works (and why it’s cool)

2FA (Two Factor Authentication) looks complicated, but it's actually really simple once you break it down.

At its core, it uses 2 things:

A realtime element (time):

A secret key:

Example secret key:
Bob1234

Make your own 2FA generator

You can actually build your own basic 2FA system in a few lines of code.

What you need

• A code editor like Visual Studio Code

• Python installed

import time
import hmac
import hashlib
import struct

secret = "Bob1234"

counter = int(time.time() // 30)
counter_bytes = struct.pack(">Q", counter)

h = hmac.new(secret.encode(), counter_bytes, hashlib.sha1).digest()

offset = h[-1] & 0x0F
code = struct.unpack(">I", h[offset:offset+4])[0] & 0x7FFFFFFF
code = code % 1000000

print(str(code).zfill(6))

When you run this, it will generate and print a 6 digit verification code directly in your terminal.