> Running a full node is the only way to assure the integrity of the currency. Another method is to use cryptographic proofs to demonstrate the validity of a b

> Running a full node is the only way to assure the integrity of the currency. Another method is to use cryptographic proofs to demonstrate the validity of a blockchain state. A lot of newer projects are taking this approach, such as the project I work on, Mir Protocol. Granted, it doesn't seem like a realistic option for Bitcoin. The community doesn't seem very open to major protocol changes, and even if it were, cryptographic proofs for Bitcoin might be prohibitively expensive since the protocol wasn't designed with that in mind.