Together with the decentralized network topography, the extensive use of cryptography is the other constitutive element that characterizes a blockchain. In particular, it is the adoption of asymmetric cryptography that allows a blockchain to achieve all of its advantages. In this chapter, we will briefly introduce symmetric cryptography, which will serve us to analyze asymmetric cryptography in depth, since it is the central aspect of a blockchain.
Let's now try to understand what aims cryptography must fulfill in general to then understand its role in the architecture of a blockchain.
