mikedao

Public Key Cryptography

The Problem: How do we communicate securely on the internet?
  - We have to encrypt our communications.
  - How do two parties who have never met, agree on a key when all of their communications are public?
  - The answer: Diffie Hellman Key Exchange. -Whitfield Diffie, Martin Hellman 
  - The first implementation of public key cryptography as envisioned by Ralph Merkle.
  
The Setup:
  - Alice wants to Talk to Bob.

mikedao

Get all requests that match :identifier
get matching user_agent_ids
get matching user_agent
os = user_agent.split(' ')[1]
count requests that match os
create hash {os => count }
display os[1..-2] + count

mikedao

1. Check to see if application is registered
2. Check to see if payload is present
3. Check to see if request is a duplicate one.
4. Sanitize payload
5. Insert payload into database.

mikedao

class Centaur
  attr_reader :name,
              :breed

  def initialize(name, breed)
    @name     = name
    @breed    = breed
    @actions  = 0
    @standing = true
  end

mikedao

Create VPC
Create Security Group
Create incoming and outgoing rules for SSH, HTTP, Sinatra and Rackup, 443
Create Key Pair
cd ~/.ssh
mv ~/Downloads/Turing.pem .
chmod 400 Turing.pem
ssh-add -k Turing.pem
Launch Instance
ubuntu 14.04

mikedao

def validator(card)
  card.chars
      .map { |n| n.to_i }
      .map.with_index { |n, index| index.even? ? n * 2 : n }
      .map { |n| n.to_s.length == 2 ? n.to_s[0].to_i + n.to_s[1].to_i : n }
      .reduce(:+) % 10 == 0 ? "Valid" : "Invalid"
end