Cryptocurrency and Privacy
- Paper due on Thursday at 11:59PM. Come ask us questions!
- Week 10 Tuesday is a final review.
- Please fill out course evaluations.
- As stated in the course policies and in the first lecture, outside resources should be cited.
- If you copy/pasted information from outside class without putting it in your own words for short answer questions, that is an honor code violation.
- If you'd like to retract a homework assignment, we will treat it as if you never turned it in. Any retractions must be communicated before the last day of the quarter (Wednesday, June 6 at 11:59PM) by emailing Tyler or me.
Plan for Today
- Cryptocurrencies and Bitcoin
- Privacy concerns
What is a Cryptocurrency?
- Currency; you can use it to buy things
- Only has value because people agree it has value
- Not run by a government or any other organization (decentralized)
- Key component to work: need to have a way to prevent "duplication" (can't use the same dollar or bitcoin twice)
- Secured by cryptography instead of government or people
- Focus on bitcoin, but there are others (Ethereum)
- Bitcoin stored in a wallet
- Sender signs intent using public-key encryption
- Processed using cryptography - computers "mine" by helping the transactions
- First computer to solve the puzzle (Proof of Work) gets some bitcoin (how new BTC are created)
- 21 million bitcoin will be created (through 2140), then shift to fees
- Optional transaction fees determine speed at which transaction is processed
- Goal: prevent double (fraudulent) transactions
- Decentralized = no master list of each bitcoin
- 200,000 computers in the cryptocurrency network must agree (consensus) and keep a list
- Block: file that records transactions
- Idea: information once recorded can't be changed (prevent fraud)
- Blocks are connected together to form the blockchain
- Removes trust from the transaction
- Other uses of blockchain
- Ethereum allows smart contracts: contracts (like a bet) that don't require a third party to enforce
- Decentralized, so no inflation or gatekeeping
- No more fraud
- Independent of local economy
- Easy to transfer funds
- Anonymous (used to be used for criminal activity)
Problems with Bitcoin
- Energy involved with mining
- Volatility as a currency
- Transactions take hours/days
- Transaction fees ($20-30)
- Used as an investment instead of a currency
- Potential for deflation
- Companies keep data on how you use their services
- Data leads to more targeted ads (more money)
- In an age of "big data" - super valuable
- Allows many services to be free (but data collected even when you pay)
- Data leads to a massive competitive advantage for companies
- Should companies get to keep information on you?
- Company employees?
- Your government (Snowden)? Foreign governments (why Google pulled out of China)?
- Other companies?
- Criminals through data breaches?
Privacy in the US
- Companies must comply with their posted privacy policies (Federal Trade Commission Act)
- Financial and health information are strongly regulated
- Control over collection/use of phone numbers and email addresses
- In the US, the only way (by law) to control what data is collected about you is to not use websites
- Know privacy controls (especially Facebook)
- European Law (nothing similar in the US)
- Ask how data is stored and used
- Request data not be used for certain purposes (such as marketing)
- Ask companies to delete information
- Notify agency and/or users within 72 hours of a data breach
- Cryptocurrencies use blockchains secured by cryptography to verify transactions
- Companies collect data to better target ads - the data is super valuable
- Privacy laws protect users' data and information