Search Results

This chapter serves as an introduction to the environment in which cryptography finds common use today. We discuss the need for cryptography, as well as the basic language and concepts that are used to describe a cryptographic system. We introduce the core security services, such as confidentiality, data integrity, and authentication, which are delivered by cryptography in order to support modern security technologies. We introduce both symmetric and public-key cryptosystems, and discuss the differences between them. Finally, we consider ways in which cryptosystems can be attacked or compromised.

This chapter analyzes how, in 1976, Whitfield Diffie and Martin Hellman suggested that one could use NP to hide one's own secrets. The field of cryptography, the study of secret messages, changed forever. Diffie and Hellman, building on earlier work of Roger Merkle, proposed a method to get around the problem of network security using what they called “public-key” cryptography. A computer would generate two keys, a public key and a private key. The computer would store the private key, never putting that key on the network. The public key would be sent over the network broadcast to everyone. Diffie and Hellman's idea was to develop a cryptosystem that used the public key for encrypting messages, turning the real message into a coded one. The public key would not be able to decrypt the message. Only the private key could decrypt the message.

The fourth chapter describes how technological decentralisation emerged with advancements in cryptography and acted as a political counterweight of resistance to the encroachment of centralised governments across (online) spaces. The decentralist worldview is shown to be rooted in the specific political geography of the West Coast of the United States that, during the latter half of the 20th century, became a crucible of counterculture and entrepreneurship. Fuelled by this vision, a monetarist desire to create fairer economies through algorithmic decentralisation gave rise to the advent of cryptocurrencies. The intersection and slippage of this technologically deterministic imaginary (preaching a freedom from hierarchy and control) with geographies of material practice is developed throughout following chapters.

Chapter 7 exposes the algorithms that are the foundations of the Internet. The Internet relies on “packet-switching” to transfer data between computers. Messages are broken into ‘‘packets’’ of data and these packets are routed across the network in a series of hops between linked computers. The advantage of packet-switching is that the network is easily extended and is robust to isolated computer failures. Data sent on the Internet is protected from errors by means of an algorithm invented by Richard Hamming. His algorithm adds information to packets, enabling receiving computers to detect and correct transmission errors. Communication on the Internet is secured by means of an algorithm published in 1977. The RSA algorithm relies on the properties of large prime numbers to prevent eavesdroppers from reading encrypted messages.

Chapter 13 investigates cryptocurrency and quantum computing. Bitcoin – the world’s first cryptocurrency - was released by Satoshi Nakamoto in 2009. Unlike conventional money, Bitcoin transactions are anonymous - maintained by a worldwide collection of computers operated by volunteers. Bitcoin took off on the black market but then migrated to legitimate business. The current value of all bitcoins is a staggering $41 billion. Strangely, no one knows who Nakamoto is – he, she, or they have yet to reveal themselves. Quantum computing was first proposed by physicist Richard Feynman in 1981. His idea was that the weird behaviour of sub-atomic particles could be exploited to perform computations. In theory, quantum computing allows huge numbers of calculations to be performed simultaneously. Google, IBM and others are now in race to build a practical quantum computer. Such a machine might well crack the encryption algorithms that currently underpin both the Internet and Bitcoin.

Chapter 1 opens the lid on Bitcoin so that all of its attributes, problems, and connotations come spilling out. At the same time, it pulls these disparate strands back into focus by outlining the many discrepancies examined in subsequent chapters. So while in some ways the chapter acts like a primer for cryptocurrencies, blockchains, and their political economies, the material laid out works to set up the book’s underlying argument: asymmetric concentrations of power inevitably form though processes of algorithmic decentralisation. In the process, a short history of Bitcoin introduces some of its key stakeholders as well as some of its core technical functions.