Hash Functions

In this lesson, we'll start learning how Ethereum works. But instead of jumping right into the technicalities of blockchain, we'll start with a foundational topic for understanding blockchains: cryptographic hash functions. While this might seem very theoretical at the moment, hash functions are used so often in Ethereum and other cryptocurrencies that it's worth spending some time to get a good grasp of this topic before we move forward.

Hash functions

A cryptographic hash function is a special algorithm that takes a binary of any size as an input, but always produces an output of a fixed size (e.g., a 32- or 64-byte number depending on the function used). The result of a cryptographic hash function is called a hash value or just a hash.