Lecture 26: Bitcoin (Part 1)

What is Bitcoin?

Designing Bitcoin: Identity

(True/False) In Bitcoin each user has a symmetric key associated with their identity.

Designing Bitcoin: Transactions

In Bitcoin, how do we make sure a user can only spend money they have?

Designing Bitcoin: Blockchain

(True/False) If instead of hashing the entire previous block in our blockchain, we just hashed part of it, this would still be secure since an attacker can’t break collision resistance.

Designing Bitcoin: Motivating Consensus

Consider a version of the protocol we’ve seen thus far, which requires two individuals working together to add a block to the hashchain. Assume there is only a single adversary, Mallory, in the network - can she double-spend via a fork?