In this problem, we consider a double spending attack on the cryptocurrency discussed in Section 5.8.2 a. Outline Trudys double spending attack as discussed in the book. Why is double spending a non-issue for non-digital currencies? b. Suppose that Trudy controls 10% of all of the computing power in the network and that Alice only requires one valid block before accepting a transaction. What is the probability that Trudys double spending attack succeeds? c. Suppose that Trudy controls a fraction p of all of the computing power in the network and that Alice requires N>=1 valid blocks before accepting a transaction. What is the probability that Trudys double spending attack succeeds?