Radio Encryption

[die@pig.jjm.com (Dave Emery)]

	Many US private and governmental radio services licensed by the
FCC permit encryption, especially if the license applicant can show some
need.  As far as I am aware, there are absolutely no requirements in
the FCC regulations mandating key escrow, disclosure, or retention or
any restrictions on the strength or type of crypto used.  At most there
may be a requirement to disclose the type and/or technical details of
the crypto system as part of a license filing, but no requirement for key
disclosure at any time. 

	As any ham knows, the amateur radio service is the one major
exception to this rule.  Hams are not permitted to encrypt or
deliberately obscure the meaning of a communication by any other
technique.  This is usually justified as a measure to protect the
amateur radio service against abuse by commercial interests who might
otherwise be able to transmit encrypted traffic on ham frequencies with
relative impugnity, and as a means of ensuring that the rules and
regulations can be enforced.  This regulation probably had its origin in
the 1920s or 1930s, however, and may have been originally actually
primarily intended to prevent use of coded long distance radio
communications by rum-runners and spies. 

	Many current generation private point to point commercial
microwave and domestic satellite systems use encryption or at least
provide it as an option; I have never heard of any requirement for key
escrow or disclosure here either.  And, of course, an increasing number
of radio delivered broadcast or multicast services such as stock
quotations and sports scores transmitted over SCA subcarriers and
satellite transmissions of cable TV programming and sports events are
being encrypted to protect the commercial interests of the copyright
holders against real or imagined losses from piracy.  I do not know
whether cypherpunks believe in intellectual property or not, but to many
others this is understandable, and in fact more understandable than
passing laws making mere interception of radio signals a crime. 

	Further, there is no current restriction preventing a user of
the current analog cell phone system from transmitting strongly
encrypted data with a modem over a voice channel or even low bit rate
encrypted digital voice.  This is not illegal or restricted by any US or
state tariffs that I have ever heard of. 

	Recently the FCC has allocated certain frequency ranges for
completely unlicensed use (notably the band between 902-928 mhz) by
devices radiating limited power.  Devices operating in this band may use
any kind of encryption the user desires and do not require anything
other than FCC type approval (you can't build them yourself or modify
them without going through a formal (and expensive) type approval
process however).  Using correct antennas and a path free of major
obstuctions such as hills or a large building these spread spectrum
devices can securely communicate over ranges measured in miles without
any kind of license being required. 

	And in the near future certain other regions of the spectrum will
open up to low power unlicensed use, again without any restrictions on
encryption.  

	I have a friend who has obtained a FCC license for using DES
encrypted HT's on the itinerant VHF frequencies allocated for temporary
business at random places use by such things as road-show crews and
construction companies; all he had to do was explain that he bids at
surplus auctions and needs to keep his future bids confidential and he
got the license without trouble.  He certainly has had no requirement
to disclose or archive the keys he uses or even certify that the radios
are actually using DES in a particular mode (he could use 3-DES).

	So it is simply not true that use of encrypted radio transmissions
within the domestic US is restricted or forbidden by treaty or even
inaccessible to private citizens of ordinary means.   Encrypted international
radio communications may be another matter, however, but domestic stuff
is fine.

						Dave Emery   N1PRE

						die@pig.jjm.com