cover image Secret Code Book

Secret Code Book

Helen Huckle. Dial Books, $14.99 (64pp) ISBN 978-0-8037-1725-1

Move over, Mata Hari. Watch your back, Mr. le Carre. Espionage is alive and well-make that ``xjiok xbg qkjj,'' in the coded language known to master spies and the readers of Huckle's ingenious book. More than 20 codes are clearly presented, from Pig Latin (everyway ildchay owsknay isthay) to Morse code (with its 1920s offshoot, the ACME code) and the ancient Greek Polybius square, a ``substitution cipher'' in which each letter is represented by a pair of numbers. Double agents in particular will want to try Superenciphering, ``using two codes or ciphers together [which] makes your secret message even more difficult to break.'' Among the more unusual entries are the high-seas code, using flags, developed by the British Royal Navy in the 18th century and still practiced; and a grille with punch-out squares, originated by a 16th-century Italian mathemetician, that reveals a hidden message when placed over an innocuous-looking text. Two press-out ``code-busters'' are included. A handsome design places solid-color borders around clean white pages; instructional photographs and art reproductions add, er, intrigue. Ages 8-up. (June)