A review by jessrock
In Code: A Mathematical Journey by Sarah Flannery

4.0

Written by a 16-year-old Irish girl who made a name for herself by doing research on cryptographic systems for an academic project, culminating in her inventing and testing out a new cryptographic algorithm. The book promises to teach some of the math involved without getting too complicated, and even tells the math-wary reader what chapters are skippable if you just want the story and not the math. The book is definitely enjoyable and engaging, although the math gets a little slow in the middle. I went into this not knowing much about cryptography and came out of it feeling like I did have some understanding of the subject. Some of the trivia she provides is also quite interesting, like the math behind ISBNs (they encode information such as the publishing house and end with an error-checking digit which, due to the length of the ISBN, requires it to be base-11, which is why the last digit of an ISBN can be 0-9 or X for 10). Straddling the middle section about math and cryptography are two sections about Sarah, her family, and her experiences presenting her research nationally and internationally, and it's interesting to see both how her family fueled her curiousity and helped keep her in check as the press was lauding her as a "genius" and trying to get her to patent her algorithm so she could "make millions."