In the last part of this series , we discussed the basic concepts of blockchain technology. In this post, we are going to discuss the evolution of blockchain and it the latter part of the post, I will introduce the concept of bitcoin technology at a high level. Hashing and Hash Functions The concept of hashing is the backbone of the blockchain technology and it helps us to speed up the searching process. Hashing allows us to map any data to a fixed size. The entity which performs hashing is called a Hash Function. For e.g, H(x) = x%n ( % is the modulo operator - returns remainder when x is divided by n ) , as it is evident that x can be of any value but H(x) will always be in the range [0, n-1] . x is called Message H(x) is called Message Digest Cryptographic Hash Function It is a mathematical algorithm that maps data of arbitrary size to a bit string of a fixed size (a hash). It is a one-way function i.e. we can find H(x) if x and n are given but if H(x) and n