Scaling Bitcoin with Subchains

Side chains offer a solution for horizontal scaling and sharding while maintaining the primary security parameters of the main chain. In the future, there will be an Internet of chains, with bitcoin serving as the root chain for different applications such as factom / proofofexistence, ChainDB, Blockstream side chains, merge mined side chains, and more. A multi-chain design offers greater scalability in general. Mike Hearn argues that either everything must be validated or nothing at all, though probabilistic verification through validating a random subset of all scripts is possible. Side chains are not a means of scaling up. Jeff Garzik is a Bitcoin core developer and open source evangelist at BitPay, Inc.