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96 pages • first pub 1972 (editions)
ISBN/UID: None
Format: Not specified
Language: English
Publisher: Not specified
Publication date: Not specified
nonfiction
history
mathematics
informative
slow-paced
Description
Explains in simple terms how to encode and decode messages in various ciphers, describes coding machines, and gives formulas for invisible ink.
Community Reviews
Content Warnings
96 pages • first pub 1972 (editions)
ISBN/UID: None
Format: Not specified
Language: English
Publisher: Not specified
Publication date: Not specified
nonfiction
history
mathematics
informative
slow-paced
Description
Explains in simple terms how to encode and decode messages in various ciphers, describes coding machines, and gives formulas for invisible ink.
Community Reviews
Content Warnings