Manual for the Solution of Military Ciphers

MANUAL FOR THE SOLUTION OF MILITARY CIPHERS is a text that was written in 1916 by United States Army Captain Parker Hitt. The book was essentially a manual for the military to improve and refine the security of their communications, specifically in the fields of cipher work. some parts of the book are now quite outdated, but the main body of the work is still highly valuable as a historic manual on cipher breaking and still of great value for amateur and professional cryptographers due to providing many basic principles of the field that are relevant even now.


 * The Book Cipher: Mentioned in the intro, but noted as being outdated for modern uses for military purposes.
 * Captain Obvious: The miner proverb Hitt cites: Gold is where you find it.
 * Keep It Foreign: An advised technique to make ciphers hard to break was to make sure its conventions would be highly unorthodox to the party who might be expected to try breaking it.
 * Older Than They Think: Nigh all substitution ciphers were noted to have origins in principles dating back to the late 15th century, no matter how original their creators assumed them.
 * Spotting the Thread: Hitt noted most ciphers written by different countries had key tells that would identify them, such as frequently used letters endemic to their language structure.
 * Spy Speak: Discussed. Hitt noted codes based on this are not very practical save for specific tactical purposes, and then only for short-term uses.
 * Technology Marches On: At the time of publication, Hitt noted codes were becoming obsolete for military use, save for brief and specific tactical codes.
 * He also noted that most codes and ciphers are not as new as their creators think, then or even now, as most of the basic principles of any modern cipher are based on precedents established centuries and even millennia prior.