Scanned Document - National Security Agency

This is an examination of codes and
ciphers as they figured in American history
prior to the twentieth century, prior to the
era of wireless or radio communication and
the advent of the electronic age. It forms
a backdrop for understanding modern
cryptology and the role of cryptology
(notwithstanding its traditional secrecy) in
the growth of this nation. Our guide is Dr.
Ralph E. Weber of Marquette University,
whose 1979 United States Diplomatic Codes
and Ciphers, 1775-1938 (Chicago: Precedent
Publishing Inc.) established him in the
forefront of students of this arcane subject.
Cryptology, the art and science of code-
making (cryptography) and code-breaking
(cryptanalysis), depends on the prevailing
state of technology and the perception of
threat:
Technology determines the means of
communications. Technology also provides
the means for protecting and the means of
exploiting intercepted communications.
Perception of threat depends upon a
number of considerations, such as the
estimated degree of risk, or the damage that
might occur, should an unintended recipient
become privy to the contents of the
communication.
The perception of threat rises naturally in
war, but it also pertains in international
relations, in business competition, in politics,
and even in personal matters, including
financial transactions. Applying technology
to protect communications (to "mask" them,
to use Thomas Jefferson's term) or to exploit
those of another party introduces other
variables, not the least of which is cost. Cost
can involve dollars of time, including
personal inconvenience. Sometimes the risk
is discounted, if the cost seems too great;
conversely, faced with the consequences of
compromised information, what seemed
Foreword
earlier too great a cost may well be dismissed
in favor of security.
America was born out of revolutionary
conspiracy. One of the principal concerns for
conspirators is communication, keeping in
touch, and doing so in confidence. As rebels
and conspirators, the young nation's leaders
had turned to codes and ciphers in an effort
to prescrve the confidentiality of their
communications. The technology of the time
was that of messenger or hand-written
correspondence, hand delivered, or by
prearranged signals, such as Revere's fabled
lanterns, "one if by land, two if by sea." The
risk was that a dispatch might fall into enemy
hands through capture of a courier, and this
did happen. Intercepted cryptograms yielded
to cryptanalysis of an elementary sort,
producing communication intelligence,
COMINT. But there was no COMINT effort as
we would understand the term today. The
technology of the time would not have
supported such a concept. (How many enemy
couriers could be scheduled for systematic
and regular capture, to justify thought of a
sustained effort?) Nor was cryptography an
organized bureaucracy; rather, it depended
upon the interest, knowledge, and
imagination of a few men. America was lucky
to have such men when it needed them. Some
were "civilians in uniform," volunteer
soldiers; most were learned men, clergy
(familiar with Greek, Latin, Hebrew),
mathematicians, scholars - some were
statesmen. Their involvement in cryptology
was generally brief, but it constituted the
seeds of American cryptology.
With the successful end of the
Revolutionary War, the occasion for
COMINT disappeared, as did the perceived
need for secrecy, in the absence of an
adversary. When the need subsequently
arose, particularly in the case of foreign