Finished Projects
Cryptographic Technologies
International Cryptography Experiment (ICE)
International Cryptography Experiment (ICE) Status Report
Trusted Information Systems, Inc.
Stephen T. Walker
August 10, 1994
The response to my April paper calling for an International Cryptography Experiment (ICE) has been very positive. This status report is the first of what I hope will be many on ICE and the circumstances surrounding it. ICE calls for a series of experiments to promote the international use of cryptography in common computer software applications (i.e., word processors, spreadsheets, electronic mail systems) in a manner that honors individual national controls on the use and export of cryptography. The general approach being advocated by numerous organizations in several countries is to separate the actual performance of the cryptographic functions from the software applications that call for encryption of specific messages or files.
The identification of Cryptographic Application Programming Interfaces (CAPIs) at various levels of software applications provides the best approach to establishing the separation needed between applications asking for cryptography and hardware or software actually performing the cryptography (see Figure 1).
ICE is an informally structured program to coordinate the many efforts underway in several countries to advance the general understanding of CAPIs and their use to promote international cryptography. ICE is not a standardization program. ICE will use whatever interfaces are available in experiments to demonstrate the effective use of cryptography. It is intended that practical standards derived from actual use will evolve from these experiments in the spirit by which Internet standards evolve.
Status of CAPI development
There are a number of examples of CAPIs that are already defined and in
use or near to being in use at this time. The National Security Agency's
(NSA) TESSERA PCMCIA card interface is a publicly available CAPI that is
entering widespread use in the US Department of Defense. At least one
example of a non-TESSERA PCMCIA card that is compatible with the TESSERA
interface specification is presently available (i.e., SPYRUS LYNKS
card). The National Institute of Standards and Technology (NIST) has
released for public comment a draft Federal Information Processing
Standard (FIPS) for Cryptographic Service Calls. The United Kingdom (UK)
Ministry of Defence (MoD) Technology Demonstration Program (TDP) has
contracted with a UK firm to specify a series of CAPI definitions for
use in the TDP efforts. Other private companies have defined or are
defining interfaces for other PCMCIA, Smart Card, or cryptographic
peripheral devices.
An early stage of ICE will identify all practical application programming interfaces and attempt to coordinate their use in experiments with commonly available software applications. To the extent possible, all publicly available interface specifications will be included in the initial set of ICE experiments.
Status of Computer Applications
Discussions have begun with a number of software application developers
with the intent of including their applications in the set of ICE
experiments. At this stage, the focus of attention has been on
identifying CAPIs and software/hardware implementations of cryptographic
functions. Until these are available there is no need for extensive
application support. As soon as a sufficient suite of CAPIs and
supporting cryptography implementations are available, interactions with
software application developers will be aggressively pursued.
Status of Government Interactions
Of essential importance to ICE is the ability to export applications
that call upon CAPIs but do not themselves contain any cryptographic
functions. This is somewhat new territory for the export control
process. If an application developer merely removes the cryptographic
software from an application (such that it could, for example, be added
back in with relative ease), export is still disallowed, in the United
States at least.
But application programs that call CAPIs are not the same as programs for which the specific cryptographic code has been deleted. In this case, the actual cryptography used is bound to the application not by the software vendor but by the user at the actual time of use. The choice of which cryptography to use is made at the time a message is sent or a file saved, not at the time of manufacture of the program.
At this time I can report that the essential issues of this proposal have been discussed with appropriate officials in the US government. It is not clear when or if a decision will be made in favor of the export of applications that call CAPIs. But I am encouraged with the level of discourse that has taken place in the past few months, and I am hopeful for a reasonable and timely outcome of this process.
Status of ICE activities
A proposal has been submitted to the US Advanced Research Projects
Agency (ARPA) to support the coordination activities of ICE and to
ensure that at least one publicly available application program is
interfaced with the various CAPIs that currently exist or are under
development. If this proposal is funded, I expect significant ICE
activities to begin this fall. Until that time we will continue to
pursue ICE coordination activities at a relatively low level of effort.
Individuals and organizations that wish to participate in ICE or to remain abreast of its activities are encouraged to contact Trusted Information Systems, Glenwood, MD, 21738 USA, or send email to ice@tis.com.
Figure 1