Restless

Long time no book reviews.... seems I never get around to reading for fun anymore. But this book was great, once started I could barely put it down. Restless by William Boyd is a spy thriller set in the years leading up to the Second World War.

The spy is a woman of many names, the story told through her daughter. The spy - Eva - leads an exciting life, first learning to be a spy and then working as a spy. Her daughter, Ruth, leads by contrast a very gray, boring life, with just odd previous members of her family showing up or one of her adult pupils trying to kiss her as excitement.

The story turns around and around, is told from two time perspectives, and filled with all sorts of details about a spy's life. And that is why I read a paragraph aloud in my Algorithms and Data Structures class this week, in the lecture on cryptographic algorithms.

I wanted to stress the point that codes can be devised that no computer will ever be able to discern, much less crack. They don't necessarily involve asymmetric algorithms and large prime numbers. Just a short exchange - agreed on in advance and transmitted through another, secure, channel - suffices.

- "My, you are looking nice today!"
- "Thank you, I just got back from a two weeks' vacation."
- "Did you go to the mountains?"
- "No, I prefer the seaside."

What message is hidden in these lines? No fair guessing if you have already read the book!