Ask HN: What cryptography book do you recommend for reading with 10 year olds?

We are looking for a Cryptography book recommendation to read with our 10 year old who loves making up his own ciphers. He loves reading adult math and science books with us at breakfast like Ignition!, Humble Pi, and The Hunt for Vulcan. All of the kids books that we've found are just puzzles, but I don't want to get something way over his head math-wise. A good history with basic theory behind the different types would be perfect. Thanks!

63 points | by mike_richards 2 days ago

33 comments

  • Daneel_ 1 minute ago
    It's not directly a cryptography book, although it includes some basic cipher guidance, but I LOVED the Usborne Spy's Handbook as a child. It's still available now. I'd thoroughly recommend it - I completely wore it out as a kid, so much so that the book fell apart, leading me to re-purchase it as an adult for nostalgia. Genuinely useful book! I still use some things from it, like estimating crowd sizes.

    https://usborne.com/au/official-spy-s-handbook-9781409584384

  • dhosek 1 hour ago
    In Code by Sarah and David Flannery (https://www.amazon.com/exec/obidos/ASIN/1565123778/donhosek). I would usually target this at bright high school kids, but I think that your kid might be a good fit for it as well from what you describe. Sarah was a high school student learning about cryptography from her math professor dad (David), and presents a great overview of cryptography from Caesar to modern public key cryptography (she came up with an idea using the fact that matrix multiplication is hard to invert for a cipher scheme although it turned out that there was an easy crack for her matrix-based cipher).
  • WillAdams 1 hour ago
    A couple from my childhood:

    - _Codes & Secret Writing_ by Herbert S. Zim

    - _Codes and Ciphers: Secret Writing Through the Ages_ by John Laffin

    - _Codes, ciphers, and secret writing_ by Martin Gardner

    There was another book on alphabets/letterforms and ciphers --- pretty sure it had a cover designed by Oscar Ogg, but blanking on the name and can't find it.

    While searching online for that found:

    Secret Writing: An Introduction to Cryptograms, Ciphers, and Codes by Henry Lysing and John L. Nanovic

    Cryptography adjacent (it's about the difficulty of deciphering a dead language), but H. Beam Piper's novella "Omnilingual" really should be part of the grade school canon --- lightly updated version at:

    https://vrici.lojban.org/~cowan/omnilingual.html

  • amingilani 22 minutes ago
    At that age, I was obsessed over Sherlock Holmes' The Adventure of the Dancing Men by Arthur Conan Doyle

    [0]: https://sherlock-holm.es/stories/pdf/letter/1-sided/danc.pdf

  • mlyle 7 hours ago
    There's an edition of The Code Book for youth: https://www.amazon.com/clp/0385900325?lv=shuf&channelId=500
    • brightball 1 hour ago
      Recommended it as well!
    • mike_richards 6 hours ago
      Thanks. I'm torn he loves reading himself, but also when we work through adult books with him. :)
      • ghostpepper 0 minutes ago
        In case anyone isn't aware there is also a regular non-youth version of this book that is excellent.
    • robterrell 6 hours ago
      Seconding this one!
  • vkaku 1 hour ago
    https://www.schneier.com/books/applied-cryptography/

    Was one of the best books I read back in the day, It wasn't only about the algorithms themselves, also about how many verification schemes worked, in an easy to understand manner.

    Today I'd say the knowledge of protocols is still valid, just that the algorithms first themselves need to be post-quantum secure.

  • yobananaboy 5 hours ago
    One of the books that got me interested in cryptography as a kid was Artemis Fowl! It might be too simple for him now, but the gnommish (glyph substitution cipher) on every page was really fun for me to figure out.
  • garrettr_ 1 hour ago
    For a 10 year old I would highly recommend Martin Gardner’s “Codes, Ciphers, and Secret Writing”: https://a.co/d/05rZPKiH

    It’s a slim volume that focuses on historical and fictional ciphers. It stars with simple shift ciphers like Caesar’s cipher, progresses to more complex substitution ciphers with examples from Sherlock Holmes and Edgar Allen Poe, then covers polyalphabetic ciphers like Vigenère and Playfair. It covers basic cryptanalysis and has practice riddles and cryptograms throughout. It even has a chapter on a variety of ways to make invisible ink, which is often an object of fascination for children around that age!

  • somenameforme 1 hour ago
    There's a whole bunch of history books around WW2, the Enigma Machine, and surrounding historical and technical details. I can't recommend any specific one, but this might be more interesting read, with more context, than a text on crypto. It's also quite neat because it's kind of like a basic cipher taken to the extreme, setting the stage for what a revolutionary (and counter-intuitive) discovery public key encryption was.
  • cryptoalex 2 days ago
    I would suggest Real-World Cryptography by DAVID WONG. It has good introduction covering basic primitives like various hash functions, MAC, KDF, then sym/asym, and so on, all the way to PQC and protocols design. A nice intro book, maybe your 10 y.o. will find it interesting.

    P.S. In fact, I was going to send that book to my friend's son who is about same age, and who got some sudden interest in cryptography recently. So it is safe to say that I am now aware of at least two 10 year olds who have interest in Cryptography. I feel a bit surprised, but in a good way :)

    • mike_richards 2 days ago
      Thanks we'll check it out.

      He started with inventing his own alphabet and language as he was learning to read and write, which eventually evolved into reinventing the Secret Decoder Ring with increasing complexity, so we want to encourage him in his adventure.

  • jedberg 6 hours ago
    Don't forget about the NSAs CryptoKids!

    https://web.archive.org/web/20100128072801/http://www.nsa.go...

    (They went offline a few administrations ago, hence the archive link)

    You can also jump around the timeline in the archive to see different versions.

    • mike_richards 6 hours ago
      Thanks, that's great. So glad for archive.org
  • jegoodwin3 1 hour ago
    For the Age, the perfect Christmas gift:

    https://www.amazon.com/Cryptanalysis-Study-Ciphers-Their-Sol...

    Helen Gaines Cryptanalysis: A Study of Ciphers and Their Solution

  • adrian_b 3 hours ago
    As a 10-year old, my introduction to cryptography was from reading a few novels by Jules Verne:

    The Giant Raft or 800 Leagues On The Amazon

    Mathias Sandorf

    A Journey To The Centre of the Earth

    After reading those, I played with the ciphers described there, i.e. I made and used the transposition grid from Mathias Sandorf and I used various Vigenère ciphers, like that from "800 Leagues On The Amazon".

    Due to the interest generated by those stories, a few years later I read various textbooks about modern cryptography.

    The book "Applied Cryptography" by Bruce Schneier is now somewhat old, so it is no longer up-to-date, but it is written in a style more accessible for newbies than most textbooks about cryptography, so I think that it would be adequate for a teenager who is good at mathematics.

  • brightball 1 hour ago
    The Code Book. It’s a great, short war history read about the history of hiding messages and eventually builds up to cryptography.
  • vmilner 5 hours ago
  • mike_richards 2 days ago
    Besides practical books does anyone have opinions about these?

    The Code Book by Simon Singh

    The Codebreakers by David Kahn

    The Mathematics of Secrets by Joshua Holden

    • dgacmu 7 hours ago
      The Codebreakers is a fantastic book and I highly recommend it. I don't know what I think of it for a ten-year-old, it's been a while since I've read it, but my memory is that it is certainly mathematically accessible, but its length and depth may make it daunting, as it probably exceeds the attention horizon of a typical ten-year-old by an order of magnitude or two. But in chunks it could work, and for an adult it's fantastic.

      It does assume a fair bit of historical context knowledge, though, much of which probably exceeds 5th grade. Probably 9th graders would have it easier as far as, e.g., familiarity with WWII, etc.

      • mike_richards 5 hours ago
        Thanks. Yeah, I'll have to flip through it. I might try Cracking Codes with Python by Al Sweigart first.
    • rubendev 5 hours ago
      The Code Book is what got me interested in cryptography and by extension computer science. I thought it was a fun and varied read.
    • helph67 6 hours ago
      There was a television series (British?) featuring some of the tales mentioned in David Kahn's book. The TV series could be a good introduction for children. Another book of interest may be Crypto by Stephen Levy - Viking Penguin 2001. Which relates how "rebels beat the (U.S.) government - saving privacy in the Digital Age".
      • mike_richards 5 hours ago
        Nice, I'll look that up he love Nova like science programs.
    • smath 5 hours ago
      Highly recommend 'The Code Book by Simon Singh'. Simon also runs a math circle online called parallel circles from the UK, that is free to attend and is fun for kids.
    • nephihaha 7 hours ago
      Simon Singh is a very entertaining writer, I'll give him that. (Also a pleasant person, I've met him once or twice.)
  • vessenes 7 hours ago
    Not a book but you could construct a little walk through some historical crypto as fun games to play. Caesar cipher, Vigenere cipher, one time pad, then learn about primes and make some repeating keys..you could do a super simple matrix example to make tiny DES s-boxes. I bet claude could come up with some games / fun little exploration things to do together, and you and your son could do a lot of fun motivating math together. You could anchor it with rewards like pictures of you and your partner or some family history or stuff that feels like a treasure hunt.

    Mine are out of the house, but I had a few who might have really liked doing something like this.. could make a nice Christmas present, the first mysterious letter..

    • mike_richards 6 hours ago
      That is a fun idea, and a great Christmas present... which is one of our goals. :)
      • vessenes 1 hour ago
        Sort of a Sophie's World for Crypto. I'm sure this would be a treasured experience.
  • advael 6 hours ago
    Introduction to Modern Cryptography by Katz and Lindell is from a pedagogical perspective one of the best-structured textbooks I've ever read on computer science topics (and in general, but my exposure to textbooks is a biased sample). It goes into the foundations of cryptographic theory and gives a good basis for understanding and contextualizing even advances that have been made since its publication. I think most children can grasp difficult material if an adult that's good at the meta-skill of teaching is helping them with it via individual attention
    • mike_richards 6 hours ago
      Thanks for the recommendation.

      "I think most children can grasp difficult material if an adult that's good at the meta-skill of teaching is helping them with it via individual attention" That's how we feel too and they appreciate being given that chance if we don't push.

  • jszymborski 7 hours ago
    Maybe The Gold-Bug by Edgar Allen Poe? Although the language might be a bit baroque.
    • buredoranna 7 hours ago
      I very much remember this, from when I was ten or so.

      In the same vein, is the "The Adventure of the Dancing Men" [1]

      [1] https://en.wikipedia.org/wiki/The_Adventure_of_the_Dancing_M...

    • lazystar 7 hours ago
      this, but for a 10 year old consider getting the Great Illustrated Classics abridged version. i read it when i was 10, and it kinda blew my mind.
    • mike_richards 6 hours ago
      Thanks. We just finished Gulliver's Travels with him, so I bet he can handle it.
  • dustfinger 7 hours ago
    Title: Can You Crack the Code?: A Fascinating History of Ciphers and Cryptography

    ISBN-10 ‏ : ‎ 1681195143 ISBN-13 ‏ : ‎ 978-1681195148

    Title: Top Secret: A Handbook of Codes, Ciphers and Secret Writing

    ISBN-10 ‏ : ‎ 0763629723 ISBN-13 ‏ : ‎ 978-0763629724

    • mike_richards 6 hours ago
      Thanks for the recommendations, Top Secret was just recommended elsewhere so we'll check them out.
  • pull_my_finger 5 hours ago
    I haven't read this title, but I've read some of the other manga guides on NoStarch and they're pretty good. Try The Manga Guide to Cryptography[1]

    [1]: https://nostarch.com/mangacrypto

  • fyltr 4 hours ago
    should you and your kid speak french or spanish, "la bible des codes secrets" by Hervé Lehning, the bible of secret codes, is a book I greatly enjoyed as a young teen. it walks you through the history of cryptography until the current times, and has a lot of examples where you can try it out yourself. it is almost not coding-oriented, with only the last 3 chapters explaining modern-day encryption, but as far as my experience goes, few ten-year old enjoy reading documentation or textbook-style books. This one is very didactic, and also an interestin tour through history.
  • hoji2012 5 hours ago
    Не удалось войти в аккаунт a kockonbaevvmunarbek@gmail.com Google не удается распознать это устройство, и нам не хватает данных, чтобы убедиться, что это вы. В целях безопасности войти в аккаунт прямо сейчас нельзя. Попробуйте войти в аккаунт из местоположения или с устройства, где вы уже выполняли вход раньше.
  • intrasight 4 hours ago
    Cryptonomicon by Neal Stephenson
    • 80fj0348i 38 minutes ago
      Absolutely not a book appropriate for 10 year olds lol
  • throwaway81523 6 hours ago
    Alvin's Secret Code by Clifford B. Hicks. That's the one that got me started. I think I read it in 3rd grade (age 8).
    • mike_richards 6 hours ago
      Thanks for the recommendation, always great to hear of books begin the journey.
    • myself248 6 hours ago
      Came here to mention this. It's not too applicable to modern/useful cryptography, but introduces a bunch of related hidden-information concepts like product date codes, which I think I actually use far more often.
  • jdkee 1 hour ago
    Neal Stephenson's "Cryptonomicon"
    • 80fj0348i 39 minutes ago
      For a 10 year old? The book where the main character does No Nut November in a prison cell and then "experiences relief" quite graphically with the love interest?
  • wltyn 4 hours ago
    B ZLZLZ XEVVP OYVQRFYB: M JFZGMZFNX QHUMH.

    U WJZI VH KZJBY QYIM HUZFGBZ.

    Key: TRENCH

  • hoji2012 5 hours ago
    Взломают акаунт хакер kockonbaevvmunarbek@gmail.com как вастанавит акаунт
  • whalesalad 7 hours ago
    Not a cryptography book but highly recommended for the young curious mind: The Cuckoo's Egg
    • mike_richards 6 hours ago
      Thanks, I've read it awhile ago, you're right he would probably enjoy the "story".
  • hoji2012 5 hours ago
    Взоломат паролы
    • hoji2012 5 hours ago
      kockonbaevvmunarbek@gmail.com
  • Theophane_Rame 5 hours ago
    the code book
  • nukular 2 days ago
    Work with your llms and figure out a “zero knowledge proof” game that can be played on paper.

    Something like that would be practical.

    • mike_richards 2 days ago
      OK, Thanks for the suggestion for a practical exercise.
      • nukular 2 days ago
        Oops and that’s “zero knowledge proof”!