This is the archived Spring 2015 version of the course. For the most recent version, see http://bitcoin-class.org.
Project 1 - Double Spending
Exercise and Discussion. Try to double spend the same bitcoin by sending it twice to your wallet address. Figure out as much as you can about what happens when the double spend transactions are attempted. See how close you can get to obtaining two verified transactions spending the same coin (e.g., can you achieve two transactions with at least one confirmation each?)
Please don't try to actually rip anyone off; only attempt double spending with your own addresses (or those of willing classmates).
Post about your experiences on below. Include links to transactions in the blockchain to demonstrate your results.