Initial version: 2024-02-10
Last update: 2024-02-10

Few years ago, starting from around 2015 [cal2021, zhafanyan2016], blockchain and blockchaining started to be a very hot topic. Probably everyone knew about this technology. Sorry, I should rather say: everyone has heard of this technology. Unfortunately, few people understood it, few people knew the basis of its operation. Therefore, in the academic year 2022/2023, I decided to introduce classes devoted to this topic on the faculty I have been working. My idea was to share with my students what I know about blockchain, even though I'm not an expert in this area. I would rather describe myself as an enthusiast who is critical to all information and tries to understand how and why something works. I approach all information skeptically and with great reserve, especially if it appears as a consequence of mass-media ans social-media confusion and is the result of sudden interest caused by unspecified factors, as was the case with exploding blockchain boom. Through my classes I wan't to say: don't repeat theories you've heard before you understand them.

It is true that the blockchain market is very attractive. Analysis show an average annual growth rate of 59.9% in the forecast period from 2023 to 2030. From a value of 17.57 billion USD in 2023, projections suggest it could surge to 469.49 billion USD by 2030. According to some other this growth is even much higher reaching rate 87.7% from 2023 to 2030, from 17.46 billion USD in 2023 to 1431.54 billion USD in 2030. [bal2023, hor2024, she2024]

I'm an academic teacher. I don't want to fool you, saying that you should learn blockchain to become a millionaire easily, because this is so east that anybody can do this in just one-mont Coursera training. Instead I want you to understand this technology. It is neither good nor bad. It is just a technology, like any other on the market and you shouldn't attribute magical properties to it.

The material presented here is an effect of hours I spent, and I'm still spending, trying to learn myself a blockchain foundations. It is still evolving and constantly changing as en effect of news, articles, books and my own thoughts. This book is an effect of my attempts to systematize the knowledge I have and save it in such a form that it will be easier for me to prepare for classes. Unfortunately, and I regret it very much, I have a very poor memory, which somehow forces me to work in this way. And since the notes have already been created (are being created), I see no reason why I should keep them for myself. If this were the case, the profession I do would make no sense. The value of being teacher is not the knowledge I have, but the knowledge I will effectively pass on to the next generations.



I address this book to people who want to understand blockchain. When presenting the material, I adhere to the following "rules":

• My approach in explaining key points is agnostic to the application of the blockchain treated it as a general technology.
• I will try to describe the core concepts in not too technical and not too theoretical way.
• I use simple practical examples explaining both underlying technologies and more complex details. Personally to understand something I have to get indispensable knowledge related to topic and see how theory works in practice. I agree with popular saying attributed to Immanuel Kant: "theory without practice is empty; practice without theory is blind".

• You will learn about the main area where blockchain may be applicable.
• You will learn about basic components required by blockchain to work at all.
• You will learn how the components are used.
• You will learn why blockchain does what we expect it should do.
• You will implement very simple blockchain to "feel" how it works.

• You will not learn how to use any special cryptocurrency or trade cryptocurrency. Cryptocurrency is just a fraction of possible application. Cryptocurrency uses blockchain but does not explain it, so from the perspective of the goals I set for myself in this book, discussing it does not bring any profits.

I, probably as most of other people except geniuses, have to "process" tones of sources of informations in the form of blogs, articles and books to learn something. It is no different in this case. What you will read in the following chapters was inspired or initiated in my head, if I may say so, by some materials, mostly books. Unfortunately, writing books is neither easy nor profitable. I strongly encourage you to buy some of the listed books if you will find them helpful or useful. These books are mentioned in bibliography [dan_2017, dre_2017, fly_2020, ant_2017, lancaw_2020, antwoo_2018, antosupic_2021]. This is how you can support and motivate Authors to spend their, very often free-of-work, time and share what they know. Remember, nothing is free even if it seems to be so. Even for "free" and "open" materials someone has to pay. Who? Very often an Author. Remember about that next time downloading "free" pdf.

Among many online sources and material I have read trying to learn blockchain technology foundations I strongly recommend [wal].



As you see, there are may good books, but none of them is as mine is. Why do I think my book is unique and worth to read? Because:

• I wrote this book not to show how smart I am, but to show it's quite simple.
• What I enclosed in this book is not abstract – I "tested" it on my students. If something was foggy or ambiguous I changed it to make clear and understandable.
• I use precise but not scientific language so everyone can read it.
• I present a real code to show that all this theory can be easily implemented (at least to the level allowing you to understand how it works; you have to put a "little bit more" effort to turn it into production ready system).

Give this book a try, and please let me know what you think. Any feedback is very much encouraged and welcomed! If you think that my time is worth this effort, you can support what I’m doing now and help me finalize this project. Please use email book@fulmanski.pl or GitHub https://github.com/fulmanp/Blockchain/issues to give your positive or negative, but in all cases constructive, feedback.

Thank you for your engagement

Piotr Fulmański