Re: CPSR Clipper Petition /rsp [one more round it is Denning -> Rotenberg -> Denning .. djf]

[David Farber <farber () central cis upenn edu>]

From: denning () cs cosc georgetown edu (Dorothy Denning)
Subject: Re: CPSR Clipper Petition /rsp
To: farber () central cis upenn edu




Dave,


I don't know if you want to continue the "Rotenberg/Denning debate" on
Interesting People, but this was my response to Marc.


Dorothy
--------
The following comments are in response to responses posted in RISKS 15.50
on my earlier comments:


> From Marc Rotenberg:
>
> The NSA is responsible for foreign signal interception.  It has no legal
> authority to conduct wire surveillance.  What are the NSA's "national
> security" interests in domestic wire surveillance?
I do not believe that NSA has any particular interest in domestic wire
surveillance.  I expect their concern is that if a product with a very
strong algorithm such as SKIPJACK were to be manufactured without keys
being escrowed, then such products would be very attractive on the
foreign black market (presumably, such products would not be
exportable) where they could interfere with foreign intelligence.
> The FBI made certain claims that cryptography was impeding criminal
> investigation conducted by wiretap.  CPSR investigated the FBI's claims by
> filing a Freedom of Information Act suit to obtain the relevant documents.
> The documents provided to us by the Department of Justice revealed that none
> of the FBI field officers had encountered any obstacles.  The Department of
> Justice has just informed us that they provided to us all relevant documents
> concerning the Clipper proposal.
In testimony before the Computer Systems Security and Privacy Advisory
Board (CSSPAB) at NIST, James Kallstrom of the FBI said that encryption
was styming the effort in more than three but less than ten of ongoing
cases.  The FBI does not give details of ongoing investigations, so this
information would not be available through FOIA.


> There is one reported case where cryptography made it difficult for law
> enforcement to obtain evidence. That case concerned reading the contents of a
> file on a hard disk after it was seized.
>
> If this is the problem that the Clipper proposal is intended to solve, then
> the key escrow scheme must be extended to every single encrypted file -- not
> just encrypted communications -- everywhere in the world.
I've heard of 3 cases now where encrypted files could not be decrypted,
but law enforcers seem to be much more concerned about communications
than stored files.  Clipper does not address file encryption.
> An FBI legislative proposal now under consideration at the White House would
> mandate a Clipper-like scheme.  That proposal is backed by fines up to $10,000
> per day and jail time.
Everything I've seen has said Clipper is voluntary.  Quoting from the standard:
"This standard does not mandate the use of escrowed encryption devices by
Federal government agencies, the private sector or other levels of government."
Dept. of Commerce, NIST, Docket No. 930659-4017, RIN 063-AB19, Approval
of FIPS 185, Escrowed Encryption Standard (EES).
> >  I support this objective.  Unfortunately, it is not
> >  possible for most of us to be fully informed of the
> >  national security implications of uncontrolled
> >  encryption.  For very legitimate reasons, these cannot
> >  be fully discussed and debated in a public forum.
>
> This assertion has never been supported by evidence.  It has been used simply
> to stifle criticism.
Certain information relating to foreign intelligence operations is
classified.  Are you saying that decisions should not be based on
classified information or that foreign intelligence information should
not be classified?
> CPSR did not participate in the inter-agency policy review.  Our position from
> the very beginning is that these decisions must be made openly.
As part of the inter-agency review, the CSSPAB was asked to sponsor
hearings on the proposal.  These were held in June.  The testimony that
was presented was given to the government.  Marc gave a presentation
at those hearings, as did David Banisar of CPSR.  Several people in
the government who have been participating in the inter-agency review
were present at the hearings.  There have been several other forums
as well, including one sponsored by CPSR last June.  Again, several
people participating in the inter-agency review were present.


> >  In the absence of understanding
> >  the national security issues, I believe we need to
> >  exercise some caution in believing that we can
> >  understand the full implications of encryption on
> >  society.
>
> This premise, if accepted, would mean that people in the United States would
> have no right to express political views when the government claimed "national
> security." Certainly, there are matters of national security that must be


I did not mean to suggest that people should not express their views.  Being
cautious is different from being silent.


As followup to what I said in RISKS, I'd like to respond to another of
Marc's comments, made in reference to the 5 of us who reviewed SKIPJACK.


> Dorothy endorsed the proposal before she joined the "review" team.  The
> group that she refers to, a White House task force, has an interesting
> history.  The majority of cryptographers asked to participate
> declined.


I believe that approximately half accepted.


My support of Clipper is contingent on it providing a very high level
of protection, including protection against compromises or abuses of
keys.  The main reason I agreed to be a reviewer was to make sure that
the system was in fact secure.  I believe the others share my concern.
Before I supported Clipper, I already knew quite a bit about how the
whole system was going to be structured, so I felt confident that the
goal of high security would be achieved.  Nothing I have seen so far
has changed my assessment.  However, if as a result of our complete
review, I come to the conclusion that the risks of Clipper are not
acceptable, I will withdraw my support.


Dorothy