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Welcome back to #TripwireBookClub. If you recall, the last book we reviewed was The Ghidra Book: The Definitive Guide, a book that I thoroughly enjoyed because I’m a huge fan of everything Chris Eagle writes. This time, we’re looking at Crypto Dictionary: 500 Tasty Tidbits for the Curious Cryptographer. I am by no means a cryptography expert, so I’ll share the thoughts of the rest of my team shortly. I will briefly give my opinion first.

I love reference books. I have a shelf that contains TCP/IP Illustrated (the box set) next to the Intel IA-32 Architecture Software Developer’s Manuals (all 6 volumes). On my desk, I have RTFM, BTFM and PTFM. So, in some ways, it feels like Aumasson wrote Crypto Dictionary for me. I love that I now have a crypto reference guide that I can pick up and check. One issue with looking these terms up online is that you have no idea if they are accurate or who the source is – after all, anyone can edit Wikipedia. Knowing who Aumasson is and the rigor of every No Starch Press book, I can trust the information I find in this book. I had only one complaint and only because a colleague pointed it out to me. Cryptography says “See Cryptology” and Cryptology says “See Cryptography.” I did not see the humor in this and would have liked to have seen a valid definition, especially for those new to the field that may pick up the book. I will say, however, that my favorite definition was Cryptid. I won’t share the definition here, but I feel like the book is worth the purchase just to read that one.

Here’s what others had to say about the book:

Crypto Dictionary 500 Cryptographic Tidbits for the Curious by Jean-Philippe Aumasson offers a quick explanation of crypto terminology. Aumasson’s book is written with a dictionary layout. This book has crypto terminology sorted in alphabetical order. This book can feel like you are reading a dictionary. However, the author provided a few ways to reduce this feeling. The author offers a few tongue-in-cheek definitions. This provides much-needed humor while going through the material. Furthermore, the additional details for some of the crypto definitions allowed the book to not feel exactly like you are reading a dictionary. Overall, I would say that this book offers a quick rundown of the crypto terminology that it contains, but additional resources will be needed if you want to learn more about a particular subject.

Rating: 3.7/5

Andrew Swoboda

Senior Security Researcher


Having previously read and reviewed Aumasson’s last book, Serious Cryptography, I was excited to have the opportunity to do the same with Crypto Dictionary. As the name implies, this is a much different type of book, focusing on breadth rather than depth of technical content. It is in fact styled as a dictionary although with a distinct lack of formality. The preface bills this as a book where the reader can open any page at random and more than likely find something new, interesting or at least entertaining. It achieves this with a wide assortment of entries including topics of not just technical but also cultural significance (see Cryptonomicon). Technical content is also broken up a bit by entertaining entries like for Twitter or the word ‘suck’ as defined by Matthew Green.

While this is arguably less serious than, Serious Cryptography, it should not be discounted as an entertainment-only book. Mixed in with anecdotes of ridiculed cryptography (see MAGENTA) and tongue-in-cheek definitions (see mining), there are many useful technical terms with plainly worded and useful definitions. The definitions shed light on these topics and provide vocabulary and context for the reader to pursue further mastery of a topic. A lot of the terms are things I had not heard of before or things I may have heard before but without context. Reading entries for topics with which I’m already familiar would also occasionally enrich my knowledge of the technology even in cases where I have had more than a little experience.

In terms of usefulness, I think Crypto Dictionary has definitely earned its place on my bookshelf next to Serious Cryptography. I can confidently say that I will be coming back to Crypto Dictionary over time as a starting point for researching “new-to-me” concepts in cryptography. I would highly recommend this book to anyone with a general interest in cryptography or needing a basic guide to ‘translate’ crypto jargon to English.

Rating: 5/5

Craig Young

Principal Security Researcher


Crypto Dictionary was a unique read. It wasn’t a standard book about cryptography that had a “read this at point A to get to point B” approach. If I had to sum this book up, I would say it was a giant appendix of random but usable information on cryptography. As I read through it, I found myself seeing acronyms that I use or read about every day, but with some interesting backstory or funny quips attached to them. I will give the author credit, I wasn’t bored reading a dictionary all about cryptography. He made the read through interesting in the aspect of giving good metaphors to relate to certain ciphers and attacks. He also brought me back to my college days when I was taking several cryptography classes by reintroducing me to Alice, Bob and Eve.

I felt like the author put a lot of thought into his definitions, descriptions and examples that not only simplified and made the concept easier to follow but also had great placement of humor to keep me interested while reading. I actually learned a lot about past encryption methods and their predecessors, which I found very interesting in how they shaped what we know and use today in modern cryptography. Overall, I found Crypto Dictionary an enlightening book that has a good balance of education mixed in with some humor. I encourage anyone who is curious about cryptography to give Crypto Dictionary a read, not only because it gives you a massive amount of information in 138 pages but also because you might find yourself laughing more than you think throughout the read.   

Rating: 4/5

Matthew Jerzewski

Security Researcher


The Crypto Dictionary is only a dictionary in the sense that it is an alphabetical list of crypto terms. What comes after each crypto term varies greatly. If you pick a term at random, you could get a highly technical and mathematical explanation of an encryption technique, or you could get the author’s commentary on the usefulness of the term without any real explanation of it. You could also get just a reference to another term elsewhere in the book that’s related but not quite the same thing. Reading this book from beginning to end was a bit of a wild ride due to the various different approaches to ‘defining’ a term. However, much like an actual dictionary, I don’t think this book was intended to be consumed that way. It isn’t intended to be reference manual for looking up a term and getting an informative explanation. You might, but you also might not. What the Crypto Dictionary is good for is exposure to a wide variety of Crypto terms that can be used as a starting point for piquing your curiosity for further research. There are plenty of historical, niche and interesting Crypto things to learn about in addition to basic terminology. Open to a page at random, and find something new to learn about.

Rating: 4/5

Darlene Hibbs

Senior Security Researcher


As with The Ghidra Book, I’m with Craig in giving the Crypto Dictionary a 5/5.

The Crypto Dictionary received a #TripwireBookClub rating of 4.34

Overall Rating: 4.34/5

Much like the last review, we don’t have any other reviews planned at this time, so if you have any suggestions, let us know on social media with #TripwireBookClub.

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