Lecture 27: Bitcoin (Part 2)
Proof of Work
(True/False) In Bitcoin Proof-of-Work, if the hash function isn’t one-way then an attacker can always win by bruteforcing a valid pre-image.
Proof of Work Example
Proof of Work Security
In Bitcoin, Proof-of-Work (PoW) requires miners to find some random number n such that Hash(block || n) has a certain number of zeroes in it. What would happen if instead, miners had to find Hash(n) for which this held?
Consensus & Mining
(True/False) Even if the network eventually switches to an alternate, longer chain, a miner will still receive a mining award
Why might having large mining pools be worrysome?
Anonymity and Conclusions
If someone bought something from you over Bitcoin, how could you track their future transactions?
Note: We won’t have time to cover certificate transparency, but for those interested see here