...h respect to any loss or damage caused, or alleged to have been caused, directly or indirectly, by the information provided on the governmentattic.o... ...o your request of 23 December 2007 to have A History of U.S. Communications Security (2 volumes) by David G. Boak, Fort George G. Meade, MD National S... ...ae DaMG.a-kLectares) IUf'il1)LlNG INSTBDCI'IOXS i COMINT Declassified <llld apploved fOJ release by NSA on 12-10-2006 plIISllant to E.O. 12958. as ame... ... and second: trarllpo.ition-keeping our original meaniDgful text, but jumbUng the pom:;oM of our words or letters or digits so they no ORIGINAL 11 !~ ... ...tion of one value for another. These range from systems whose security stems from a few letters, words, or digits memorized in somebody's head, throug... ...ion of them is: Code: "A substitution cryptosystem in which the plaintext elements are primarily words, phrases, or sentences, and the' code equivalen... ...of them. Let's look at a couple of codes: 1. The simplest kind, called a "one-part code", simply lists the plaintext meanings alphabeti­ cally (so tha... ...velop some interim suppreBlicm measures for their product liDes, and the Committee published two lists: one contaiDing equipments which were for· bidd... ...h and breadth of South Vietnam were many cryptoppbica1ly unique NESTOR nets (i.e., different key lists) to comply with doctrioa1 rules Iimitiq net siz...

...This publication consists of a series of lectures prepared and given to interns and other employees by Mr. David G. Boak in 1966. Mr. Boak is uniquely qualified to discuss the history of the US COM_SEC because he has participated significantly in most aspects of its modern development over the past twenty years....