Horizontal and Vertical Scaling

If bridges are not secure at the moment(>$1.5B stolen), why are people still building and using them? The core issue is scalability, limited capacity of a monolithic blockchain (i.e. Ethereum) that we are still far from mass adoption. When it comes to scaling, in addition to the rollups and sharding, it has roughly two categories: horizontal scaling and vertical scaling. These solutions all aim to offload heavy computation to other scaling chains.

With horizontal scaling, we have two options:

1. Interoperability -- offloading computation & processing completely to other chains - i.e. connecting monolitic L1s to other L1s, roll ups.
2. Sharding ---- slitting itself for parallel processing

With vertical scaling, we have:

1. L2s - rollups, plasma, state channel (if it is still a thing), that leverages the security of the monolithic L1
2. scaling chains - side chains (have its own security) and modular blockchains (off-load part of the L1 functionality such as data availability etc. We can think of such setup as legos)

In essence, interoperability solutions are a critical piece of blockchain scalability from an ecosystem perspective. It is the connection point that allow other scaling solution to even be connect to the overloaded L1s, enabling computation offloading. Here wanted to share a very good summary on what bridges and some of its design categories: federated (external trust), light client (native trust to destination chain), liquidity network (modular on top of light client implementation) - https://medium.com/1kxnetwork/blockchain-bridges-5db6afac44f8

Reference

https://medium.com/1kxnetwork/blockchain-bridges-5db6afac44f8