Mastering Corda

Chapter 2. Essential Corda and Blockchain Cryptography

Cryptography is the science (and art) of protecting information, whether that means concealing information by making it visible only to intended parties or validating the integrity of a message to tell whether or not it was tampered with. Cryptography is the bedrock on which the ability to protect digital information rests. To the uninitiated, modern cryptography will seem like magic for the promises and assurances it provides, but underneath it all is rigorous mathematics that enables technologies like blockchain to deliver on their unique value propositions. Source code and cryptography tools used in this chapter can be found at http://masteringcorda.com.

For blockchain, cryptography plays a central role in delivering immutability, consensus, transaction signing and verification, data synchronization, and more. Cryptography allows for mining in the cases of Bitcoin and Ethereum, faster synchronization of transaction information between nodes of a blockchain, airtight transaction integrity and—probably the most important and revolutionary—double-spend protection, where a party receiving a digital asset is assured it wasn’t also transferred to one or more other parties.

When it comes to blockchain, cryptography is used in a number of ways, but the two fundamental techniques you should be most familiar with are hashes and asymmetric keys.  Both of these are instrumental in providing blockchains the firepower they need to ensure ...