Civilian Ownership of Cryptography
[Page last modified: October 27, 1995]
Some people believe that cryptography was government property until the
public key revolution in the 1970s. To the contrary, a careful reading of
David Kahn's ``The Codebreakers'' (Macmillan, 1967) shows that cryptography
was invented over 3000 years ago by civilians, and that it has been dual-source and dual-use for its entire history.
However, there are some differences between the civilian and
government histories:
- At least prior to the computer age and possibly still today,
government employees (military and diplomats) sent the vast majority of
encrypted messages while civilians did the most encrypting of non-messages
(e.g., diaries, inscriptions, instructions for finding buried treasure, ...).
- By volume of activity, government agencies have done the majority of
cryptanalysis while civilians have done the most invention of new systems.
- By quality of activity, government agencies have done the very best
cryptanalysis while civilians have frequently invented the strongest
systems. Government agencies, like the NSA in the US, might recently have
taken the lead in inventing strong systems -- but since their work is
classified, we will not know for sure for a number of years if not
centuries.
The government lead in cryptanalysis is partly because governments have
traditionally been the only ones in a position to intercept communications
and one needs intercepts in order to do cryptanalysis; partly because
civilian inventors typically prefer to spend their time admiring the
cleverness of their cryptosystem designs rather than trying to break them.
Academic (civilian) cryptology has started to include some decent
cryptanalysis -- not to read intercepted traffic but to find strengths and
weaknesses of new invented systems -- but it is likely that governments
will continue to lead in this area. The need to read the messages of a
shooting enemy gives a drive which academics will never feel. In addition,
academic results are published and therefore added to the secret body of
techniques available to the government analysts.
In spite of this long history with civilians inventing new systems and
governments learning how to break them, at least the US government is now
expressing public shock over the prospect of civilians' having access to
strong cryptography. Apparently we civilians are supposed to to end an
almost 4 millenium tradition and stop inventing, publishing and using
cryptography as strong as we can make it.
Back to the previous page (``Attempt versus Succeed'').
Carl Ellison
--- cme@acm.org