The philosopher: Two women stand talking to each other. Woman 1: "Privacy" is an impractical way to think about data in a digital world so unlike the one in which our soci- Woman 2: SO BORED.
The crypto nut: A figure stands behind another sitting at a desk, who is working a computer. Sitting figure: My data is safe behind six layers of symmetric and public-key algorithms. Standing figure: What data is it? Sitting figure: Mostly me emailing with people about cryptography.
The conspiricist: A figure stands talking to a woman. Figure: These leaks are just the tip of the iceberg. There’s a warehouse in Utah where the NSA has the *entire* iceberg. I don’t know how they got it there.
The exhibitionist: Two official-looking figures are looking at a console. One is sitting; another is standing behind the chair. Console screen: Mmmm, I sure hope the NSA isn’t watching me bite into these juicy strawberries!! Oops, I dropped some on my shirt! Better take it off. Google, are you there? Google, this lotion feels soooo good. Operator: Um.
The sage: Beret guy is sitting with a friend at a restaurant table. Beret guy: I don’t know or care what data *anyone* has about me. Data is imaginary. This burrito is real.
In particular we present the Diffie-Hellman key exchange and the ElGamal crypto system, which are both widely used in practice. The Diffie-Hellman key exchange is used to initiate secure connections such as the secure communication between web browser and web server. ElGamal is applied in the encryption of email and other forms a secure communication.