Cryptography Technology

This chapter provides detailsCryptography of cryptography technologies, with a focus on blockchains, Bitcoin, cryptocurrencies, Ethereum, and smart contract systems. In the first section, a brief history of asymmetric cryptography is provided. The second section introduces public key cryptography types, including ElGamal cryptography, Rabin cryptography, and elliptic-curve cryptography. In addition, an introduction of authentication protocols, point-to-point protocol (PPP), authentication, authorization, accounting (AAA) protocols, and centralized network authentication is provided. The third section provides a description of the most popular Rivest–Shamir–Adleman (RSA) public key and private key asymmetric cryptography technology, including details of cryptographic procedures, simple numeric example of RSA encryption and decryption, and an example case of a Man-In-The-Middle (MITM) attack. Since MITM attacks are frequently used in cryptocurrency and smart contracts intrusions, it is important to understand the attack mechanism and how it can use asymmetric cryptography in its advantage to obtain important user information, including login IDs and passwords. As asymmetric cryptography is used in blockchains, Bitcoin, cryptocurrencies, Ethereum, and smart contract systems, the content of this chapter serves as a foundation for the following Chap. 8 (titled “Blockchains”) and Chap. 9 (titled “Bitcoin”) as well as Chap. 10 (titled “Smart Contracts & Ethereum”).