CS 5436 / INFO 5303: "Privacy in the Digital Age"

Assignment 4  - due May 6, 2015
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* Surveillance

  - What is the biggest vulnerability that many websites have (including
    US government sites) making their network traffic vulnerable to
    surveillance?

  - What is the "Stingray" device that Chris Soghoian mentioned in his talk?
    How does it work?

  - Is protecting individuals from surveillance a technological problem or
    a political problem?  Explain.

* Genetic privacy

  - How did Yaniv Erlich's group re-identify anonymous genomes?
    Describe the entire process.

  - In his talk, Yaniv mentioned the Homer et al. attack on genetic privacy.
    What was that attack and how was it different (goals, techniques, etc.)
    from the one performed by Yaniv's group?

* Bitcoin

  - Can a digital cash system have all three of the following properties:
    decentralization, anonymity, double-spending prevention?
    Give examples (including hypothetical) of systems that have each 
    combination of two properties.

  - What is a bitcoin address, mathematically?
    If this address doesn't have the receiver's identity, how does the
    sender know whom to talk to?

  - Why do we need the block as a separate abstraction?  
    Why can't each transaction have its own block?

  - Any node can start working on calculating the next block. Do nodes
    talk to each other to figure out who will do it?  If so, how? 
    If not, doesn't it lead to wasted (duplicated) effort?

  - What are the two ways in which you can lose the ability to spend
    your bitcoins?  Try to find real-world examples.

  - Suppose your private keys get stolen, i.e., copied by a thief. 
    Now both of you have the same information. Then who has the money?

  - Let's say you successfully get away with theft. 
    What are the various steps you can take to hide your tracks?

  - What are the various forensic techniques (based on future transactions
    that they have to make in order to spend the stolen bitcoins) that one
    can use to try to uncover the thief?

  - How many Bitcoin transactions have there been so far? How many public
    keys have participated? What is the current total value of Bitcoins?

  - What are some of the prominent bitcoin-based businesses/services and
    what are their functions?