(Including Amazon links, but just for convenience, buy wherever you want)

Code by Petzold (https://www.amazon.com/Code-Language-Computer-Hardware-Softw...) - non-technical (in the sense it isn't something to "work through"), covers a lot of interesting topics. Especially approachable for that age.

Elements of Computing Systems by Nisan & Schoken (https://www.amazon.com/Elements-Computing-Systems-second-Pri...) - more technical (has content to work through). I've read the first edition, not the second. Has a companion site: https://www.nand2tetris.org. It's well-written, and a motivated high schooler could work through it.

The Code Book by Singh (https://www.amazon.com/Code-Book-Science-Secrecy-Cryptograph...)

The Codebreakers by Kahn (https://www.amazon.com/Codebreakers-Comprehensive-History-Co...)

I was always interested in ciphers and such as a kid so those two books got my attention when I found them in high school/college. I'm a bit fuzzy, now, about which one I was more interested in but both were good books. (I still have them, may give them a re-read next month.)

There are a few others I have in mind, but just can't recall the titles at the moment.

http://www.amazon.com/The-Codebreakers-Comprehensive-Communi...

A good read about the crypto behind the Enigmia and other encryption approaches. A fun read.

The Codebreakers: The Comprehensive History of Secret Communication[0] by David Kahn is probably the best book in this area. Be warned it sits on many bookshelves but due to its length few are the number that have finished it, none the less it is an extremely rewarding read. It has oddles and oddles of stories about cryptographers you have never heard of doing awesome things, including the history and personalities behind many of the Black Chambers of Europe.

It puts the Code Book to shame.

[0]: http://www.amazon.com/The-Codebreakers-Comprehensive-Communi...

Really a better list is by tom his own self: http://www.amazon.com/lm/R2EN4JTQOCHNBA/ref=cm_lm_pthnk_view...

My recommendations would add:

http://www.amazon.com/The-Codebreakers-Comprehensive-Communi... by David Kahn. Many stories of the whole history of secret communications, with lessons in op-sec, not changing the codes frequently enough, they can't possibly break this.

The John LaCarre http://en.wikipedia.org/wiki/John_le_Carr%C3%A9 books. Do you remember the point where someone says to Smiley "There is no reason to think that they tapped the phone" to which Smiley replies "There is Every reason".

A must read, I tell my students in my Security Awareness training classes is The Cuckoo's Egg http://www.amazon.com/The-Cuckoos-Egg-Tracking-Espionage/dp/.... Examples like default service accounts on Dec Vax with username Field and password Service. Note when this is written and are our habits really any better with junk hung on the internet? Concepts pioneered in his book, as effective as they are, are not practiced. Note the alarms going off, ignored, at a large retailer last thanksgiving. Or another retailer recently, "Wait, what, we are being attacked? I didn't feel anything".

Most vulnerable is the thinking "Well, they can't get our X because <thing we did>". I have a matrix of attacker motives and what they are after. There motives and targetsyou haven't thought of.