2. Outline
● What is cryptography?
● Why use cryptography?
● Secure instant messaging with OTR
● Secure text messaging with TextSecure
● Secure web browsing with Tor
● Other projects
3. ● “The enciphering and deciphering of
messages in secret code or cipher”
● In practice, encrypting data in such a way
that only the party you’re trying to
communicate with can decrypt it
● Everyday examples: online banking
What is Cryptography?
4. Why Cryptography?
● Security
○ Online banking
○ (Most sites; don’t want password stolen)
● Privacy
○ Personal privacy
○ Bloggers in Egypt
○ These days… all of us
■ Regular people, whistle-blowers, reporters, etc
5. Secure IMing with OTR
1. On Windows or Linux, install Pidgin
- URL: http://pidgin.im/
2. On Mac OS X, install Adium
- URL: https://adium.im/
- Download OTR plugin here: https://otr.
cypherpunks.ca/
6. Secure SMS with TextSecure
● Available for Android
● iOS version (for iPhone, iPod Touch, and
iPad) currently in development
1. Search “open whisper systems” in Play Store
2. Install TextSecure (and later, RedPhone)
7. Secure Web Browsing
1. Install Tor at https://www.torproject.org/
2. DEMO (run it, visit a website)
● Browse the web
○ Yes, it’s that simple
8. Other Projects
● Secure email with PGP
● Secure file storage with TrueCrypt
● Secure cloud storage with SparkleShare
○ Alternative to Dropbox, which is joining PRISM
● SOON
○ CrypTag: Encrypted, Taggable, Searchable
Web Storage
