Bits to Bitcoin: How Our Digital Stuff Works, by Mark Stuart Day

The networked digital world in which we find ourselves is complex and can be confusing to the uninitiated. Just what happens when you type a query into a search engine? How is music converted from analogue into digital format and back again? How can I ensure that my financial transactions are secure when carried out online? What is Bitcoin anyway?

Any one of these questions could support an entire volume in its own right – and frequently does. In this compendium, however, Mark Stuart Day sets out to address these and many other matters in a relaxed, conversational and essentially nontechnical manner.

Making few assumptions about pre-existing knowledge, he builds a picture of our digital environment from the ground up, taking care to introduce us to the physical concepts that underpin the technology without delving too deeply into their hardware implementation.

Having established a set of principles, the text introduces the simplest form of software – a basic linear program operating in isolation – before adding complexity in the form of multiple processes, additional users and other challenges. This allows Day to gently ease us into the consideration of recursion, limits, interrupts and the many other elements that make up more complex software environments.

Once we have reached this point, the networking of systems is the natural progression. This is handled with style and at some length, with welcome attention to the essential but often overlooked logic behind data communication and inter-networking.

The structures of internet protocols and packet-switching are covered in just enough depth to make sense and be useful to non-specialists, without exposing them to the full arcane detail of the architecture.

The explanation of how complex networked systems operate and are managed brings home just how much can go wrong – indeed it sometimes seems surprising that anything ever works at all.

While much of the logistical detail of network management is routinely hidden from the user, the discussion in this text may make readers more sympathetic to the plight of those largely unsung experts who maintain our digital services. Networked digital environments need to be kept safe and, happily, the later chapters of the book carry a useful analysis of the problems of trust inherent in such systems.

This discussion includes lessons from history and a nod to current controversies over privacy and politics – while issues of identity proof and trusted communication also get explored, along with some pertinent examples.

The text is rounded off with an effective couple of chapters that consider the processes around cryptocurrencies in general and Bitcoin in particular. This is the culmination of the grand tour of digital processes that Day gives us – but those who buy books based on the title alone should note that Bitcoin is the destination of the text and not its main topic.

Concepts are frequently explained by analogy, which may prove helpful to those without any formal background in the field. Just occasionally, however, I found the explanation more complex than the topic it was seeking to address – but, as the author himself suggests, “if this analogy doesn’t work for you, just ignore it”.

John Gilbey teaches in the department of computer science at Aberystwyth University.

Bits to Bitcoin: How Our Digital Stuff Works
By Mark Stuart Day
MIT Press
368pp, £24.00
ISBN 9780262037938
Published 28 August 2018