Welcome to Cryptographic Hash and Integrity Protection!
This course reviews cryptographic hash functions in general and their use in the forms of hash chain and hash tree (Merkle tree). Building on hash functions, the course describes message authentication focusing on message authentication code (MAC) based on symmetric keys. We then discuss digital signatures based on asymmetric cryptography, providing security properties such as non-repudiation which were unavailable in symmetric-cryptography-based message authentication.
This course is a part of the Applied Cryptography specialization.

From the lesson

Cryptographic Hash Function Applications

Building on the previous module defining cryptographic hash functions, this module review its uses and applications. We will first describe hash chain, which chains multiple hash functions in sequence, and apply hash chain for generating one-time passwords using a scheme called S/Key. Then, we will use hash functions to construct a binary tree and describe hash tree, also known as Merkle tree. Lastly, we will review the applications of hash function and hash tree for decentralized digital currency in the forms of cryptocurrency or bitcoins.