8.3 Use Cases

As stated above, Merkle trees are especially useful in distributed, peer-to-peer systems where the same data should exist in multiple places. These systems use Merkle trees or variants on the Merkle tree in their implementation.

Git is a popular version control system mainly used by programmers. All of the saved files are saved on every user's computer at all times. So, it's very important to check that these changes are consistent across everyone's computer.

Merkle trees can be used to check for inconsistencies in more than just files and basic data structures like the blockchain. Apache Cassandra and other NoSQL systems use Merkle trees to detect inconsistencies between replicas of entire databases. Imagine a website that people use all over the world. That website probably needs databases and servers all over the world so that load times are good. If one of those databases gets altered, then every single other database needs to be altered in the same way. Hashes can be made of chunks of the databases, and Merkle trees can detect inconsistencies.