I just randomly picked a chapter discussing a topic I'm somewhat familiar with (the one on TLS handshakes), and I'm not impressed with what I'm seeing.

I don't think anybody that doesn't already know the basics of TLS would be able to make sense of it as presented there: There's an implicit assumption that an RSA public key is used for key establishment that's never mentioned, and the diagram (which is sloppily drawn too) doesn't help things either.

In the end, "a" secret key is used to encrypt something – but the core of TLS key establishment (again, only the RSA variants) is how that key is agreed upon using only the server's public key. That's arguably the entire algorithm here (the rest is protocol negotiation)!

Judging from the table of contents it seems that the first half of this book covers basic CS stuff (what is an algorithm, Big O notation, sorting and searching, data structures etc) and then discusses some machine learning basics before looking at the more recent deep learning architectures. I would not buy this book as there are plenty of (better) online resources and even better books IMHO such as the books from Bishop or Marsland.