This field manual is intended as a training text in basic cryptanalytics and as a reference for cryptanalysts in military occupational specialty (MOS) 98C and related MOSs. The proponent of this publication is Headquarters, United States Army Training and Doctrine Command (TRADOC). Send comments and recommendations on DA Form 2028 (Recommended Changes to Publications and Blank Forms) directly to Commander, United States Army Intelligence School, Fort Devens (USAISD), ATTN: ATSI-ETD-PD, Fort Devens, MA 01433-6301.Link (Thanks, Steve!)
Update: Frank sez, "I read with interest the discussion on Military Cryptanalysis. I was in the next to the last US Army class (1976) for Military Occupational Specialty (MOS) 98B which taught us to become military cryptanalysts. Just before I retired from the US Army Reserves in 2002, I was the last trained Army cryptanalyst in service. Our "bibles" of training and reference were written by William F. Friedman (Friedman's contributions thereafter are well known-- prolific author, teacher, and practitioner of cryptology. Perhaps his greatest achievements were introducing mathematical and scientific methods into cryptology and producing training materials used by several generations of pupils. His work affected for the better both signals intelligence and information systems security, and much of what is done today at NSA may be traced to William Friedman's pioneering efforts.)"