There are many possible approaches we’re looking at:
- Succinct blockchains, and similar work by StarkWare
- Block DAG protocols such as SPECTRE and PHANTOM
- Ethereum-style sharding
- I’ve been working in my spare time on an idea that separates the consensus protocol into two layers – a “transaction feed” protocol and a “block consensus” protocol. It’s primarily designed to improve security against 51% attacks but may also help scalability if it works out, and it’s complementary to the succinct blockchain idea.