Bitcoin is the first blockchain protocol, invented by Nakamoto in 2008. It has excellent security properties, but it has horrible confirmation latencies. A transaction on the Bitcoin ledger can take hours to confirm. There have been many efforts in speeding up Bitcoin but they compromise on key security properties of Bitcoin. This lecture series is about Prism, our solution to the problem.

In this lecture series, you will learn:

• what is the goal of a blockchain protocol?

• how do we formalize the security properties of a blockchain protocol?

• how do we prove that Bitcoin is secure?

• why does Bitcoin have very bad latency?

• how to speed up Bitcoin while keeping its security properties?

• how are ideas from information theory, such as law of large numbers and typicality, useful for blockchains?

No background on blockchains and consensus theory is assumed.