[Book] Código Fonte Bitcoin — line-by-line study of the source code (PT-BR)

[Isaque Cruz]

Hello everyone,

I'm a computer science teacher from the interior of Maranhão, Brazil. Over the past months I wrote a technical book called Código Fonte Bitcoin — a complete, line-by-line study of the Bitcoin source code, written in Portuguese. It walks through the codebase from Satoshi's original 2009 client to the modern Bitcoin Core, file by file, covering transactions, blocks, consensus, the script interpreter, the P2P network, mining, the wallet, and the historical evolution — including the 2010 value-overflow incident, the 2013 fork, the migration from OpenSSL to libsecp256k1, SegWit, and Taproot.

The complete table of contents is available in this PDF, so you can see the full structure and depth of the work in detail:
https://drive.google.com/file/d/1YR_tFuNG5y4r9vaRDHVmDqxW_mY-e2sX/view?usp=drive_link

I'm sharing this here as a contribution to the community, with two goals in mind:

1. I would genuinely value technical review. This forum is home to people who understand the code better than anyone. If any of you finds inaccuracies in how I describe the code or the protocol, I want to correct them. Accuracy matters to me more than anything else.

2. I hope the material can serve as a study and teaching resource. In-depth technical material about Bitcoin's code is scarce in Portuguese. I wrote it hoping it could help students, developers, and educators — and especially those who want to study the codebase closely, line by line.

I'm happy to answer any questions about the content, methodology, or any specific chapter. Any feedback, critical or otherwise, is truly welcome.

Thank you for building and maintaining this space.

— Português — PT-BR

Olá a todos,

Sou professor de computação do interior do Maranhão, Brasil. Nos últimos meses escrevi um livro técnico chamado Código Fonte Bitcoin — um estudo completo, linha por linha, do código-fonte do Bitcoin, em português. A obra percorre o código do cliente original de Satoshi, de 2009, até o Bitcoin Core moderno, arquivo por arquivo, cobrindo transações, blocos, consenso, o interpretador de script, a rede P2P, a mineração, a carteira e a evolução histórica — incluindo o incidente de overflow de 2010, o fork de 2013, a migração do OpenSSL para a libsecp256k1, o SegWit e o Taproot.

O sumário completo da obra está disponível neste PDF, para que possam ver a estrutura e a profundidade do trabalho em detalhe:
https://drive.google.com/file/d/1YR_tFuNG5y4r9vaRDHVmDqxW_mY-e2sX/view?usp=drive_link

Compartilho isto aqui como uma contribuição à comunidade, com dois objetivos: primeiro, porque valorizo profundamente a revisão técnica deste fórum — se alguém encontrar imprecisões na forma como descrevo o código ou o protocolo, quero corrigi-las, pois a precisão me importa acima de tudo. Segundo, porque espero que o material sirva como recurso de estudo e ensino, já que há pouquíssimo material técnico aprofundado sobre o código do Bitcoin em português — especialmente para quem deseja analisar o código de forma minuciosa, linha por linha.

Fico à disposição para responder qualquer dúvida sobre o conteúdo ou capítulos específicos. Toda crítica é bem-vinda.

Obrigado por construir e manter este espaço.

[ABCbits]

I can't read Portuguese, so i only can recommend you to also create a thread about your book on local board Português (Portuguese) if you want more feedback. But i'm not sure you could get valuable feedback since PDF you share only contain table of contents.

[Danish Ali]

I can't read Portuguese, so i only can recommend you to also create a thread about your book on local board Português (Portuguese) if you want more feedback. But i'm not sure you could get valuable feedback since PDF you share only contain table of contents.

Exactly he will find people that can give him feedback on the entire content, and not only the summary. It is very hard to find in-depth bitcoin-related materials in Portuguese. Keep up the good work.


By the way, as soon as that chapter is accessible I'll gladly read it. It's one of those topics that is commonly treated incorrectly, even in English, specially because it's not really related to a value-overflow in the check of the value but rather on the check of the sum of the outputs. It's not difficult to understand what happened in 2010, but it's quite common to find incorrect descriptions. Given the focus on technical accuracy of your work I thought it might be an idea to point that out. Cheers!

[Isaque Cruz]

I can't read Portuguese, so i only can recommend you to also create a thread about your book on local board Português (Portuguese) if you want more feedback. But i'm not sure you could get valuable feedback since PDF you share only contain table of contents.

Thank you for the suggestion. I've followed your advice and also created a topic in the Portuguese section of the forum.

You're right that the shared PDF contains only the table of contents — I shared it mainly to show the structure and scope of the work. I completely understand that a full technical review requires access to the actual content, and I'm working on making sample chapters available so the community can evaluate the writing itself, not just the outline. I appreciate you taking the time to respond.

I can't read Portuguese, so i only can recommend you to also create a thread about your book on local board Português (Portuguese) if you want more feedback. But i'm not sure you could get valuable feedback since PDF you share only contain table of contents.

Exactly he will find people that can give him feedback on the entire content, and not only the summary. It is very hard to find in-depth bitcoin-related materials in Portuguese. Keep up the good work.


By the way, as soon as that chapter is accessible I'll gladly read it. It's one of those topics that is commonly treated incorrectly, even in English, specially because it's not really related to a value-overflow in the check of the value but rather on the check of the sum of the outputs. It's not difficult to understand what happened in 2010, but it's quite common to find incorrect descriptions. Given the focus on technical accuracy of your work I thought it might be an idea to point that out. Cheers!

Thank you so much for the kind words and the thoughtful comment — it means a lot, especially coming from someone who clearly understands the subject. You're absolutely right about the 2010 overflow: the vulnerability was not in the value check itself, but in the summation of the outputs, and it's remarkable how often that detail is described incorrectly, even in English. That precision is exactly what I tried to bring to the whole book.

Good news: the book is already available. There's a free sample you can read on Amazon Kindle, so you can get a feel for the writing and the approach.

Beyond that, I'd be genuinely happy to share a portion of the material with you directly. In fact, I'm planning to translate a few chapters into English — explaining how specific parts of the Bitcoin code work, in your own language — so the international community can evaluate the content, not just the structure. If you'd like, I can send you a translated excerpt as a PDF when it's ready.

Feel free to reach me at criptoicm@gmail.com or on LinkedIn: https://www.linkedin.com/in/icmoficial — thank you again for the encouragement. It genuinely motivates me to keep going.

[Danish Ali]

Thank you so much for the kind words and the thoughtful comment — it means a lot, especially coming from someone who clearly understands the subject. You're absolutely right about the 2010 overflow: the vulnerability was not in the value check itself, but in the summation of the outputs, and it's remarkable how often that detail is described incorrectly, even in English. That precision is exactly what I tried to bring to the whole book.

Good news: the book is already available. There's a free sample you can read on Amazon Kindle, so you can get a feel for the writing and the approach.

Beyond that, I'd be genuinely happy to share a portion of the material with you directly. In fact, I'm planning to translate a few chapters into English — explaining how specific parts of the Bitcoin code work, in your own language — so the international community can evaluate the content, not just the structure. If you'd like, I can send you a translated excerpt as a PDF when it's ready.

Feel free to reach me at criptoicm@gmail.com or on LinkedIn: https://www.linkedin.com/in/icmoficial — thank you again for the encouragement. It genuinely motivates me to keep going.

Thanks for the explanation. It's nice when an author takes time to explain something rather than glossing over it.

I will definitely look at the sample on Kindle. Send an excerpt of the translated part and I will be glad to look at that too. If there are things that strike me, both technically and in general, I will be more than happy to tell you what they are.

Being precise is important since it is a technical book that will be used as a reference. Good luck with the translation, that's a lot of work.

[Isaque Cruz]

Thanks for the explanation. It's nice when an author takes time to explain something rather than glossing over it.

I will definitely look at the sample on Kindle. Send an excerpt of the translated part and I will be glad to look at that too. If there are things that strike me, both technically and in general, I will be more than happy to tell you what they are.


Hi Ali,

Thank you again for your kind words and for the interest in the material.

As promised, I've prepared an English translation of Chapter 18 — the one on CVE-2010-5139, the value overflow incident you mentioned. Since it was precisely the topic you brought up, I thought it would be the ideal chapter to share first. You can read it here:

https://drive.google.com/file/d/1tdwqGyMQjc6uiLqH8znjg0uV1o4ekZHj/view?usp=sharing

I'd genuinely value your feedback: whether the translation reads well, whether the technical accuracy holds up, and any criticism you might have. Getting the wording right in English matters to me as much as the content itself.

And if there's real interest from you or others in having the complete work translated into English, I'd be glad to take on that effort. It would be an honor to bring the full book to the international community.

Looking forward to your thoughts. Best regards.

[NotATether]

It seems like a good book, despite me not understanding Portuguese.

Have you considered publishing it with Bitcoin Magazine Books?

https://store.bitcoinmagazine.com/collections/books 

It would probably be a better hosting place than a Google Drive.

[Isaque Cruz]

It seems like a good book, despite me not understanding Portuguese.

Have you considered publishing it with Bitcoin Magazine Books?

https://store.bitcoinmagazine.com/collections/books 

It would probably be a better hosting place than a Google Drive.

Thanks for the tip! I didn't know Bitcoin Magazine Books existed, honestly. It does look like a way better home for the book than a Google Drive link — I only used the Drive to quickly share a sample here for feedback.

I'll definitely reach out to them and see what happens. I'm always open to advice and tips like this, so feel free to share anything that comes to mind. Appreciate you pointing me there.