How does Google Authenticator work?

Patryk’s blog delves into Google Authenticator:

When you’re accessing services over the WEB – let’s pick GMail as an example – couple of things have to happen upfront:

  1. The server you’re connecting to (GMail in our example) has to get to know who you are.
  2. Only after getting to know who you are it’s able to decide what resources you are allowed to access (e.g. your own email inbox, your CalendarDrive etc.).

Step 1 above is called authentication. Step 2 is authorization (server can authorize only after successful authentication).

Using apps like Google Authenticator is all about step 1. And you can think of that step as logging in to your GMail account.

What problem are we solving?

Authentication is typically performed using one (or more) of the following approaches:

  1. What you know? – The server “tests you” by asking about something only you are supposed to know (e.g. username and password). That’s the most common approach. You’re presented with a login form where you enter your credentials.
  2. What you have? – The server tests you by making sure you have something that you’re supposed to have (e.g. a secret of sorts embedded in the bowels of Google Authenticator installed on your smartphone). Only you are supposed to have physical access to your phone. If you don’t (in other words you can’t open the app and type the code), authentication fails.
  3. Who you are – The server tests your biometrics. This could be done using a fingerprint reader in your smartphone/laptop, face ID in your iPhone etc.

Read more in the post here.


Stop breadboarding and soldering – start making immediately! Adafruit’s Circuit Playground is jam-packed with LEDs, sensors, buttons, alligator clip pads and more. Build projects with Circuit Playground in a few minutes with the drag-and-drop MakeCode programming site, learn computer science using the CS Discoveries class on code.org, jump into CircuitPython to learn Python and hardware together, TinyGO, or even use the Arduino IDE. Circuit Playground Express is the newest and best Circuit Playground board, with support for CircuitPython, MakeCode, and Arduino. It has a powerful processor, 10 NeoPixels, mini speaker, InfraRed receive and transmit, two buttons, a switch, 14 alligator clip pads, and lots of sensors: capacitive touch, IR proximity, temperature, light, motion and sound. A whole wide world of electronics and coding is waiting for you, and it fits in the palm of your hand.

Join 30,000+ makers on Adafruit’s Discord channels and be part of the community! http://adafru.it/discord

Have an amazing project to share? The Electronics Show and Tell is every Wednesday at 7pm ET! To join, head over to YouTube and check out the show’s live chat – we’ll post the link there.

Join us every Wednesday night at 8pm ET for Ask an Engineer!

Follow Adafruit on Instagram for top secret new products, behinds the scenes and more https://www.instagram.com/adafruit/

CircuitPython – The easiest way to program microcontrollers – CircuitPython.org


Maker Business — Supply delays have made their way inland with railway bottlenecks

Wearables — Light up the outside

Electronics — Current limiting!

Python for Microcontrollers — Python on Microcontrollers Newsletter: CircuitPython 7.0.0 Released and More! #Python #Adafruit #CircuitPython @micropython @ThePSF

Adafruit IoT Monthly — WFH Stress Monitor, Helping Parkinson's Patients with IoT, and more!

Microsoft MakeCode — MakeCode Thank You!

EYE on NPI — Maxim’s Himalaya uSLIC Step-Down Power Module #EyeOnNPI @maximintegrated @digikey

New Products – Adafruit Industries – Makers, hackers, artists, designers and engineers! — JP’s Product Pick of the Week — 4pm Eastern TODAY! 9/21/21 @adafruit @johnedgarpark #adafruit #newproductpick

Get the only spam-free daily newsletter about wearables, running a "maker business", electronic tips and more! Subscribe at AdafruitDaily.com !



No Comments

No comments yet.

Sorry, the comment form is closed at this time.