A tale of two sides of 2FA

@tech_christine A tale of two sides of 2FA It can
be the best of security, or the worst of security

@tech_christine What you will learn ✓ What is 2FA/MFA ✓
How to secure your accounts ✓ What are the 2FA types ✓ How to protect users and secure an application ✓ Potential testing steps ✓ 2FA development best practices "...it was the age of wisdom, it was the age of foolishness..."

@tech_christine Taking notes or pictures Asking stupid questions https://christine-seeman.com/talks Things
you don't need to worry about "...it was the epoch of belief, it was the epoch of incredulity..."

@tech_christine London and Paris

@tech_christine User and Developer

@tech_christine

@tech_christine Back to the beginning To when you signed up
for

@tech_christine

@tech_christine What was the hacker up to? Calling your mobile
provider

@tech_christine On the phone with your mobile provider... Using social
engineering

@tech_christine Now they have all the access... Sim swap/sim hijacking

@tech_christine

“ @tech_christine We learned that SMS-based authentication is not nearly
as secure as we would hope, and the main attack was via SMS intercept Christopher Slowe Reddit chief technology ofﬁcer and founding engineer August 2018

@tech_christine What is authentication? The process of verifying that someone
or something is the actual entity that they claim to be. - OWASP.org (these people know what they are talking about when it comes to security)

@tech_christine ... but what are the different factors of auth?
1. factor is knowledge (i.e. your password) 2. is the other method choice - Possession (token/soft token) - Identity (biometrics)

@tech_christine 2FA == 2SV == MFA 2FA = Two factor
authentication 2SV = Two Step verification MFA = Multi-factor authentication What about all those other acronyms...

@tech_christine Why didn't 2FA help? •SMS was used •2FA wasn't
even enabled

@tech_christine • Most common • Most compromised • Not recommended
by NIST since 2016 SMS

@tech_christine If SMS wasn't bad enough •SS7 (network shared by
every telecom) has it's own vulnerabilities •Text messages that are sent can be intercepted

@tech_christine Let's figure out all the ways to hack it...
1. Sim-swap (aka what just happened to us) 2. Port-out scam 3. Brute force on the application itself 4. Exploit SS7 weakness

@tech_christine Time-based One Time Password aka app based aka soft
token • Authy • Google Authenticator • 1Password TOTP

@tech_christine • Associated with certain authorized devices • Not visible
on a locked phone screen Push Based

@tech_christine Token based Physical keys that can auth • USB
drive • near-ﬁeld communication • Many use U2F (Universal 2nd Factor)

@tech_christine OTP vs U2F

@tech_christine OTP U2F • User has physical device • Strong
security from public key cryptography • No personal information associated with a key • Users type in codes • Set up and provision required • Secrets stored, providing a single point of attack

What would you change now?

@tech_christine Secure Your Account 1. Use long password/passphrase 2. Secure
with alternate authentication method 3. Use a VOIP number 4. Don't reuse passwords 5. Pin/password protect phone provider Keep on being @awesome

@tech_christine But wait... Now you are the developer at jiffygram
(an insta rival) How do you secure your users from all the bad stuff out there?

@tech_christine • Developers • Designers • Infrastructure • Managers •
Not just info sec! Security is everyone's job

@tech_christine Back to your security basics 1. Strong passwords/passphrase #
2. Don't make them be rotated 3. Store the hash securely 4. Only store sensitive data that you need ⛔

https://xkcd.com/936/ @tech_christine

@tech_christine Why this helps •Greater entropy = harder to brute
force the password •Passwords should be hard to guess, but easy to remember •Extra length + randomness allows for more entropy (strength)

Do this @tech_christine

@tech_christine

Not this ☹ @tech_christine

⬆ that is 6 a's @tech_christine

Not this either @tech_christine

@tech_christine Let's talk about password hash encryption • Just an
algorithm that takes data and produces fixed-size output • Some hashes are stronger then others • MD5/SHA-1 = + • SHA-256/512-bit SHA-2= , • If possible with performance, use an adaptive one- way function

@tech_christine Strong recommended adaptive functions Argon2 PBKDF2 Scrypta Bcrypt Head
on over to OWASP.org for more details

@tech_christine ...a user lost their phone/app access/token • Recovery codes
to the rescue! - • Allows access to application • Shown once, used once

@tech_christine lessons learned 2FA Implementation @tech_christine

@tech_christine Rate limiting prevents brute force attacks @tech_christine

@tech_christine Use a truncated exponential back-off algorithm @tech_christine

@tech_christine What is an exponential back-off algorithm?

@tech_christine Code example in Ruby login_request if retries <= max_retries
retries += 1 sleep (retries + rand(100)/1000) retry else raise "You've hit your max retries!" end

@tech_christine Get user buy-in

@tech_christine

@tech_christine ✓ Make it easy opt in ✓ Make it
easy to add ✓ Make it visible

@tech_christine Do this

@tech_christine Not this American Express OpenShift Netﬂix Pandora Pinterest Spotify
Target Best Buy Freshbooks State Farm AT&T 2FA

@tech_christine Enforce authentication on all pages

@tech_christine • For editing/removing of 2FA require credentials • If
authentication does fail, be generic in error response Moar authentication

Do this "Login failed - invalid user ID or password"

Not this "Login for User foo: invalid password" "Login failed,
invalid user ID" "Login failed; account disabled" "Login failed; this user is not active"

@tech_christine Users with the most amount of privilege, 2FA is
a requirement not optional

@tech_christine 2FA can help but... • Can only improve security
if you are following secure password practices • Some 2FA methods are more secure then others

@tech_christine Thanks for having me! All the organizers and volunteers
deserve 2 2 2 Tyson Reeder for the final graphic @tysondreeder For references and further reading checkout https://christine-seeman.com/talks

@tech_christine getﬂywheel.com/about/careers

@tech_christine What questions can I answer?

code!!

@tech_christine Twilio API Example

@tech_christine The Ruby One Time Password Library Example

@tech_christine

@tech_christine But you need to get this code to your
user...

@tech_christine Authy One Touch API Example

@tech_christine QR Code Rendering https://github.com/whomwah/rqrcode ROTP: TOTP https://github.com/mdp/rotp Twilio Ruby
API https://www.twilio.com/docs/libraries/ruby Auth Ruby API https://github.com/twilio/authy-ruby

A tale of two sides of 2FA

A tale of two sides of 2FA

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