CS251P - Lab 1 Questions
To complete the lab, please answer the questions below.
How long did your timed hashcash take to create mined2.txt, in seconds? *
If you saw "1m27.683s" as the output of time, enter 87.683 as your answer.
For each additional bit of Proof Of Work (POW) security that you create, how much longer do you have to work on average?
Clear selection
Which of the following hash functions is the function Bitcoin uses for its POW block header hashing?
Clear selection
In Bitcoin, what cryptographic technology do you use to prove that you own bitcoins in order to spend them?
Clear selection
What does Bitcoin use Hashcash-style proof of work for?
Clear selection
Given the above Poisson distribution regarding Bitcoin block generation, which of the following statements are true:
As of September 2015, new blocks on the Bitcoin block chain had 67 bits of proof of work. If creating a hash demonstrating 25 bits of proof of work security takes on average 77 seconds on a typical CPU without a hardware mining chip, how long would it take on average for it to generate a hash with 67 bits of security using a typical CPU? (Python is installed on the 21 Bitcoin Computer if you want to invoke its REPL to perform a calculation; otherwise, feel free to use a calculator installed on your laptop.)
Clear selection
Never submit passwords through Google Forms.
This form was created inside of 21.