Cracking Codes

by Diana Kimpton

First the ancient Greeks hid messages under their hair. Then Mary Queen of Scots completely lost her head because of a cracked code. Now computers create codes no human can crack. This revealing guide... This description may be from another edition of this product.

• Format: Paperback
• Language: English
• ISBN: 0439981840
• ISBN13: 9780439981842
• Release Date: January 2003
• Publisher: Hippo/Scholastic
• Length: 160 Pages
• Weight: 0.25 lbs.
• Dimensions: 7.8" x 0.4" x 5.1"