1.
LET’S ENCRYPT!
WAIT. WHY? HOW?
@NancyThanki

2.
WHAT IS HTTPS

3.
HTTP PROTOCOL + SECURITY
▸ SSL/TLS ( Secure Sockets Layer /
Transport Layer Security)
▸ keeps your passwords,
communications, and credit card
details safe between your computer
and the servers you’re
communicating with on the other
side.
▸ still speaking in HTTP, but the
communication is encrypted and
decrypted

4.
HOW DOES IT WORK?
HELLO —> CERTIFICATE EXCHANGE —> KEY EXCHANGE
1. ClientHello message
▸ aka the information the server
needs to connect to the client via
SSL
▸ server will respond with a
ServerHello i.e. similar info including
the cipher suite and version of SSL
to be used
2.Certificate Exchange
▸ the server needs to prove its identity
via its SSL certificate*
▸ does it either (a) implicitly trust or
(b) is it verified by one of many CAs
3. Key Exchange
‣ Encryption via a symmetric
algorithm using a single key
* the client may also need to prove its identity, but not always

5.
WHAT’S THE POINT?
▸ HTTP requests and responses can now be
sent through an encrypted plaintext
message
▸ i.e. verifies that you’re talking directly to
the the server you think you’re talking to
▸ But because only the other side knows how
to decrypt this message, Man In The Middle
Attackers are unable to read or modify any
requests that they may intercept.
▸ i.e. ensures that only that server can read
what you send and only you can read
what it sends
Diffie–Hellman Key Exchange

6.
WHILST THE LITTLE GREEN PADLOCK
AND THE LETTERS “HTTPS” IN YOUR
ADDRESS BAR DON’T MEAN THAT THERE
ISN’T STILL AMPLE ROPE FOR BOTH YOU
AND THE WEBSITE YOU ARE VIEWING TO
HANG YOURSELVES ELSEWHERE, THEY
DO AT LEAST HELP YOU COMMUNICATE
SECURELY WHILST YOU DO SO.
Rob Heaton

7.
SIGNIFICANCE OF SSL

8.
▸ if you see encrypted traffic today,
you can generally assume there is a
reason.
▸ by encrypting everything you give
cover to those who need it
▸ for example political dissidents

9.
SNOWDEN LEAKS

10.
PRIVACY AS A
RIGHT

11.
FREEDOM OF
SOFTWARE*
* well respected within the WordPress community

12.
FREEDOM OF
PRIVACY

13.
FREEDOM
TO USE
SOFTWARE
+
FREEDOM
TO USE IT
PRIVATELY

14.
NEVER “JUST”
A BLOG

15.
HOW DOES SSL WORK?

16.
HOW DOES SSL WORK?
WHY DOES IT PROTECT SENSITIVE INFORMATION?
1. 2 key encryption
▸ private key and public key agree on a key for this exchange
▸ symmetric algorithm with asymmetric encryption
▸ anyone can encrypt using the public key, but only the
server can decrypt using the private key
2. digital signature is “signed” by another authority
3. self-signing

17.
WHAT IS A “CA”?
(AKA CERTIFICATE AUTHORITY)

18.
“A NOTARY
FOR THE WEB”

19.
WHAT IS “LET’S
ENCRYPT”?

20.
WHAT IS “LET’S ENCRYPT”?
SETUP OF A DOMAIN VALIDATION (DV) CERTIFICATE*
1. Download Let’s Encrypt on your server that has the address
www.oohshinywebsite.com:
sudo apt-get install lets-encrypt
2. You run it as sudo telling it you want to get a certificate for
your domain
lets-encrypt oohshinywebsite.com
* DV Certificate = “the CA checks the right of the applicant to use a specific domain name. No company identity information is vetted and no
information is displayed other than encryption information within the Secure Site Seal.” There are other types of certificates with varying requirements.

21.
SO…HOW DO YOU
ENCRYPT YOUR
SITE?

22.
SHARED HOSTING
‣ Bluehost
‣ GoDaddy
‣ Pantheon
‣ LiteSpeed
‣ SiteGround
‣ Media Temple
‣ Flywheel
‣ WP Engine
‣ DreamHost
‣ LE’s community list

23.
HOW TO ENCRYPT YOUR SITE
VPS AND OTHER SERVER SETUPS
▸ nginx - https://www.digitalocean.com/community/tutorials/
how-to-secure-nginx-with-let-s-encrypt-on-ubuntu-14-04
▸ Apache - https://www.digitalocean.com/community/
tutorials/how-to-secure-apache-with-let-s-encrypt-on-
ubuntu-14-04
▸ Centos vs Debian/Ubuntu - https://www.linode.com/docs/
security/ssl/install-lets-encrypt-to-create-ssl-certificates

24.
WORDPRESS.COM
It’s already done.
Learn more here and here.
Sign up here

25.
COMMON ISSUES

26.
THE BAD
▸ No wild cards, i.e. difficult in multi/
load-balanced setup
▸ Renewal every 90 days
THE GOOD
▸ Easy to setup
▸ Free to use
▸ Good for single server
setups

27.
COMMON ISSUES
JETPACK
▸ change WordPress settings
▸ Dashboard > Settings > General
▸ site URL, WordPress URL
GOOGLE SEO
▸ your search rankings vs any modicum of care you have for
your audience

28.
FAQS

29.
FAQS
I SET IT ALL UP. DOES THIS MEAN I WON’T BE HACKED?
No. Absolutely not.
WILL IT MAKE MY SITE SLOWER?
Not really.
WHAT’S THE DIFFERENCE BETWEEN “LET’S ENCRYPT” AND PAID
SSL CERTIFICATES?
Nothing technically. But within things like PR or insurance…
kinda.

30.
COMMON
MISCONCEPTIONS

31.
COMMON MISCONCEPTIONS*
AUTHENTICATION
“A proper SSL certificate also provides authentication. This means you can be sure that you
are sending information to the right server and not to a criminal’s server.”
INTEGRITY
“because it’s now over HTTPS, and you’re protecting against MITM attacks you can be
assured that the information is in fact the information you’re meant to get.”
ENCRYPTION
“it encrypts the information as it’s being transferred from the browser to the web server.
This is known as encryption in transit, and talks to nothing about encryption at rest.”
* Read Tony Perez’s article :)

32.
COMMON MISCONCEPTIONS*
PHISHING
if the website housing the phishing page has https, and it is verified, it will show the user
that lovely green padlock.
NATION STATE ATTACKS
“My advice, assume everything you do online — HTTPS or HTTP — is being monitored.
IN CONCLUSION
It’s definitely a critical piece of the overarching security wheel associated with website
security, but it’s not going to stop websites from getting hacked, the distribution of
malware or keep website owners safe.
* Read Tony Perez’s article :)

33.
CROWDFUNDING
LET’S ENCRYPT
GITHUB

34.
SOURCES
▸ http://robertheaton.com/2014/03/27/how-does-https-actually-work/
▸ http://security.stackexchange.com/questions/11464/getting-a-root-ca-accepted-in-systems-and-
browsers
▸ http://robertheaton.com/2015/04/06/the-ssl-freak-vulnerability/
▸ https://blog.hartleybrody.com/https-certificates/
▸ https://www.cryptologie.net/article/274/lets-encrypt-overview/
▸ https://letsencrypt.org/getting-started/
▸ https://www.youtube.com/watch?v=OZyXx8Ie4pA
▸ https://www.globalsign.com/en/ssl-information-center/types-of-ssl-certificate/
▸ https://medium.com/@kevinsimper/review-of-getting-free-https-with-let-s-encrypt-5515f74be5f6#.
5qzjv4bc8
▸ https://perezbox.com/2015/07/https-does-not-secure-your-website/