Elementary account of ciphers, history, types, etc., with 151 examples of ciphers and codes. Solutions. Good introduction for beginners.
Here's a sample of other books in this Dover category
Puzzles in Math and Logic by Aaron J. Friedland 100 original problems in math and logic, featuring permutations, combinations, properties of numbers, algebra, solid and plane geometry, logic, and probability. Even accomplished mathematicians are likely to find some surprises here. 31 drawings.
The Ultimate Dot-to-Dot Book by Barbara Soloff Levy These 45 full-page brainteasers, designed for all ages, combine letters of the alphabet with numbers that go well over 100. The result? A diverting array of ready-to-color pictures — animals, buildings, vehicles, more.
Pool Simplified, Somewhat by George Fels Clear, well-illustrated text describes placement of hands, feet, and cue; ways to aim and bank shots; basics of pocketing. 18 halftones. 63 black-and-white line illustrations.
Alien IQ Test by Clifford Pickover Challenging, provocative exercises in mental acuity include such mind-bogglers as "Cosmic Rosetta Stone" and "Alien Ants in Hyperspace." "The most original — and challenging — puzzle book for years." — Scientific American. Solutions.
Entertaining Mathematical Puzzles by Martin Gardner A mixture of old and new riddles covering a variety of mathematical topics: money, speed, plane and solid geometry, probability, topology, tricky puzzles, and more. 65 black-and-white illustrations.
