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FIPS key recovery meeting (long)
Forward from: [email protected]
Date: Mon, 9 Dec 1996 15:03:27 -0800
From: "John A. Thomas" <[email protected]>
Subject: FIPS key recovery meeting (long)
John Taber and I attended the first meeting of the technical
advisory committee to develop a Federal Information Processing Standard
(FIP) for the federal "key management infrastructure." The meeting was
held December 5 and 6, 1996 near the Dallas/Fort Worth Airport. Although
the official documents referred only to "key recovery" instead of "key
escrow", representatives used both terms interchangeably.
The committee is an advisory body to the Dept. of Commerce. Its
recommendations pass through the National Institute of Technical Standards
(NIST). The charter states membership will be no more than 24, so the ten
"federal liaisons" present are apparently not considered members of the
committee. The chairman is Stephen Kent, chief scientist for information
security at BBN Systems.
The other members of the committee were employees of various
computer and computer-security firms, including Sun Microsystems,
Microsoft, Intel, Lucent Technologies, Cisco Systems, Digital Equipment,
IBM and Motorola. Some security related firms were Trusted Systems,
GlobalKey, and CygnaCom. Officials from Chase Manhattan Bank and Visa
were also present. The only academic member was Dorothy Denning of
Georgetown University.
The government liaisons included Michael Gilmore of the FBI, Jan
Manning of NSA, and representatives of NIST, the Federal Reserve Bank, and
the Defense Information Systems Agency. Some representatives were from
agencies having no apparent need for cryptography, and therefore key
recovery, such as the Small Business Administration and the Social
Security Administration. Kent later questioned why the SBA would need key
recovery when it had no need to store encrypted data. SSA needs
encryption only when it receives confidential information over insecure
systems.
Mary Good of the Commerce Department opened the meeting with a
speech charging the committee to develop a federal key-recovery standard
that can be extended to "public policy". Good urged the committee to
confine itself to technical issues only, and arrive at a standard that
could be implemented and would not be merely theoretical. Good also asked
for "transparency" in key recovery, and a couple of the government
liaisons mentioned this as well. Kent's opening remarks included the
comment that the FIPS would only deal with crypto key recovery, not
recovery of digital signatures, or with public key certification.
Most of the rest of the first day was taken up with introductions
and comments by the members and liaisons. The general tenor of comments
from corporate representatives was that key recovery had not been
important to their customers, and while they did not oppose a key recovery
standard for the government, they did oppose any effort to make it
mandatory or make it a requirement for export. Some differed on whether
an export requirement would be a problem.
Some typical comments follow. GlobalKey (which runs a private
encrypted mail system) said using key escrow would be against is policy,
and its customers would not accept it. Oracle stated it had had no
requirement for key escrow from customers and saw no need for key escrow
from its customers. It supported software-only solutions, and emphasized
they must have no classified content. Motorola stated it was important
not to impact the performance of wireless systems. Motorola advocated an
open system supporting multiple algorithms and opposed the trusted
third-party concept. Microsoft said it was pragmatic, willing to provide
key recovery if customers want it, but it definitely does not want it
mandated, nor tied in with export licensing. The Digicom member assumed
the committee was not concerned with individual privacy rights vis-a-vis
the corporate employer's power to recover an employee's encrypted message.
Jan Manning of NSA and Patricia Edfors of Treasury said the
government had a corporate interest in key recovery like any other
business, as well as for national security or law enforcement purposes.
Manning agreed there was no place in the FIPS for concern over individual
privacy rights and urged the committee to avoid privacy issues.
Kent said another issue the committee would face was the
timeliness of any response required to a key-recovery request. Gilmore of
FBI says the FBI's need for timeliness would vary, depending on the
investigation. Denning said that data other than law-enforcement related
messages could need timely recovery, citing encrypted medical data, or
encrypted data from some kind of sensor. Another parameter for timeliness
would be the number of requests made in a given time.
Although the issue was not explicitly debated, the commercial
members seemed to feel that key recovery should be directed to stored
data, while the government representatives were clearly using the term to
cover both stored data and communications. Someone asked how session keys
in a communication system were archived, and Denning remarked she didn't
know of any system which archived session keys. The following morning,
Kent said the issues included key recovery for storage, key recovery for
communications, and key recovery for staged delivery (email). This seemed
to remove the doubts some members had about the scope of the proposal. We
were left wondering how key archiving could possibly work in
communications networks. Consider a system where encrypted packets arrive
in any order, with different keys and different key expirations.
After a commenter asked for clarification of who the users of the
new standard were assumed to be, Kent stated: "The government wants the
FIPS so that industry will produce products that government can use, and
others will use as well." When another commenter pointed out that a user
could defeat a key-recovery system with superencryption or other means,
Kent said "...we have to be willing to let [that case] slip through the
cracks."
Some participants attempted to distinguish between key backup and
key recovery, the latter being the case where the parties to the
communication are themselves unwilling to give up keys. Denning responded
that "key recovery _is_ backup." The distinction seems to be about who is
a party to the communication--the corporation whose employee has lost his
keys, or the employee himself. Confusion on this point may exist because
the members didn't distinguish the case where an entity using key recovery
doesn't care about it in particular cases, but another entity, government,
very well might.
Kent asked if the new standard should require a data recovery
field in encrypted messages or files, and if so, should there be check for
integrity of this field. Requiring a recipient to check this would
encourage senders to use the standard. Someone asked how a recipient
could check if a sender were, in fact, escrowing data, even if the field
were present. Others said requiring a data-recovery field would make
compatibility difficult for older systems, or "...those choosing not to
use key recovery." Some expressed concern for the impact on system
performance of sending extra bits. Miles Smid of NIST once referred to
the data-recovery field as a "LEAF," invoking some laughter from those
recalling Clipper's "law-enforcement access field."
Following a question on interoperability with systems not using
the standard, Manning of NSA said the new export law required products to
interoperate only with products using key recovery. This brought some
irritated responses from the commercial members. One asked if the
government had some bottom line the committee would have to accept if
there were to be a FIPS. Manning said NSA had some requirements, and he
assumed the FBI did as will. Kent suggested the government side put
together a position paper. A member then asked who the customers of FIPS
were supposed to be; given the government's special requirements, why was
industry input even needed? Smid of NIST said industry input was needed,
or no one would build systems for the government to use; also, the
government may be involved in key recovery in commercial systems where
"...public safety is involved." (It seemed plain that "public safety" in
this committee is a code word for "law enforcement").
Kent suggested that if private parties want to operate
key-recovery services (apparently meaning escrow services), they would
have some negligence defense if they used a federal standard.
On the following day, December 6, Dorothy Denning presented a
high-level schematic of key recovery associated with key fields and
encrypted data. The schematic was thrown together the night before. She
promised to make it available on her web page
(www.georgetown.edu/~denning/).
Patricia Edfors of Treasury spoke about federal public key
infrastructure pilot projects. She also described an "Emergency Access
Demonstration Project," which was to "demonstrate the viability of key
recovery, as a security service, for federal business applications." The
project is to last 9-15 months, beginning August 1996. There will
apparently be participation between certain government agencies and some
private firm. Edfors said no attempt would be made to recover digital
signature keys, create a key management infrastructure, or mandate which
cryptography is used. However, "export requirements" will apply to all
plans.
Kent wondered why the government would need key recovery for
itself. He seemed to feel that key recovery for an individual's worksation
is a data protection issue (backups) rather than true key recovery.
Members mentioned a few cases where an employee was unable to decrypt his
files, but no one knew of a case where an organization was unable to
obtain shared data (e.g., a database), because it was encrypted. Other
members seemed reluctant to accept his distinction. They seem to view key
recovery as a way to audit proper use of organization assets by employees,
or to protect the organization from malicious acts of employees, or to
recover data if a custodian is run over by a bus.
Discussions continued to frame the issues for the project and
assign functional tasks for sub-committees. Gilmore of the FBI said most
key-recover issues would arise (for law enforcement) in the context of
search warrants, not wiretaps, although the latter could be very
important. In a question as to how long escrowed or archived keys should
be kept, Gilmore said as long as the data existed, which might be
indefinitely. When pressed, Gilmore said this was because some crimes
have no statute of limitation. We thought some members might be mentally
calculating storage requirements for session keys in a large
communications system, if key storage and indexing was to be indefinite.
Manning of NSA said the National Archives, for example, would have
to have access to recovery keys forever. No one asked why the National
Archives might be archiving encrypted data.
Boland of GlobalKey also asked about keys to encrypted voice or video.
No one seemed to have thought of this before.
Kent wrapped things up with a list of issues for discussion at
the next meeting. These included:
--the threat model
--interoperability
--key recovery agents
--performance issues, computation and bandwidth
--algorithm independence
--enforcement measures
The next meeting will be held in the San Francisco area on
February 19 and 20, 1996. Before then the members will confer by email
and attempt to set up working groups to present papers on particular
topics.
The meeting ended with an opportunity for public comment. None
was offered.
Our opinion was that the only reason for the existence of this
project was the insistence of the government, primarily the law
enforcement and state security agencies. Private industry seems to feel
there is little demand for a key-recovery standard, since those needing it
can implement it themselves. Industry representatives were obviously
worried about export restrictions requiring key escrow, and possible
attempts to make it mandatory in some way. As corporations use encryption
more and more, there will obviously be a need to develop key recovery
systems inside the firm. The justification for a federal standard,
however, seems weak.
We felt that this project would probably end in failure, through
inability of the industry and government parties to compromise, or if a
standard did issue, few private firms would use it. It's even doubtful
a standard could be completed and adopted before private systems are
firmly in place. Is the whole thing just more of the government's
increasingly delusional effort to control private cryptography, or does
someone besides the security agencies really want a standard?
The committee will post information at www.crsc.nist.gov. We can fax a
copy of the materials handed out. We'll try to answer any questions by
email (or phone, if you're really in a hurry).
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John A. Thomas | (972) 263-4351 | [email protected]
Bowles & Thomas, L.L.P. | Voice | CompuServe 75236,3536
410 N.W Eleventh St. | (972) 262-6520 |
Grand Prairie, Tx 75050 | Fax | PGP public key available
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=======> After January 1, 1997:
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John A. Thomas | (972) 387-8880 | [email protected]
Dolce & Thomas, L.L.P. | Voice | CompuServe 75236,3536
5720 LBJ Fwy., Suite 470| (972) 387-8881 |
Dallas, Texas 75240 | Fax | PGP public key available
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