IN CODE

A young Irishwoman’s account of the mathematical studies that made her Young Scientist of the Year.

Flannery, now a first-year student at Cambridge, grew up solving logic puzzles posed by her father, a math teacher (and her collaborator here). In the beginning chapters, she offers the reader a selection of those brainteasers, many of which depend on mathematical reasoning. So when her high school science teacher recruited her to enter Ireland’s Young Scientist competition, Sarah’s father steered her toward a project with a strong math basis: cryptography, the encoding and decoding of messages. This once-cumbersome process is now handled by sophisticated computer programs based on number theory—especially the factoring of very large numbers. Sarah decided to concentrate on the programming aspect, to give herself hands-on experience with the computer work. But first she had to learn the relevant mathematics. To bring the reader up to speed, the authors step back from Sarah’s story to present the mathematical foundations of modern cryptology: prime numbers, factoring, and other arcana of number theory. This section is in many ways the meat of the story, accessible to anyone not totally allergic to equations. As Sarah learned the math, she spotted an alternative to the standard RSA algorithm on which modern cryptology is based, and soon her project turned into an exposition of her new method—which in time won her honors as Young Scientist of the Year not only in Ireland, but in all of Europe. The latter chapters tell of the competitions, her preparation and her bouts of nerves, her genuine surprise at winning, and the sometimes-exasperating aftermath as the media discovered her and turned her (for a while, at least) into a celebrity.

A charming story, well worth slogging through the heavy loads of math.