Ask HN: What real innovation in CS can be attributed to Bitcoin?

Not an expert in the field, my question is: Can some real ground breaking innovation in Computer Science be attributed to Bitcoin and its successors?

People claim it to be: * Trustless, Proof of Work * Immutable append only ledger (Blockchain) * Smart Contracts

Are any of them new concepts?

While solving their problems, has the Crypto community invented any new general purpose Algorithms (or Data Structures) that could be used elsewhere?

I'm curious to understand those Algorithms.