Ex Parte Epstein

Board of Patent Appeals and Interferences

Sep 24, 2004

08994878 (B.P.A.I. Sep. 24, 2004)

The opinion in support of the decision being entered today was not
written for publication and is not binding precedent of the Board.
Paper No. 31
UNITED STATES PATENT AND TRADEMARK OFFICE
____________
BEFORE THE BOARD OF PATENT APPEALS
AND INTERFERENCES
____________
Ex parte MICHAEL A. EPSTEIN
____________
Appeal No. 2003-1829
Application No. 08/994,878
____________
ON BRIEF
____________
Before THOMAS, GROSS, and BLANKENSHIP, Administrative Patent
Judges.
GROSS, Administrative Patent Judge.
DECISION ON APPEAL
This is a decision on appeal from the examiner's final
rejection of claims 5 through 8, which are all of the claims
pending in this application.
Appellant's invention relates to a method and system of
utilizing private keys in a network environment wherein the
private keys are not permanently stored on the user's equipment.
Claim 5 is illustrative of the claimed invention, and it reads as
follows:
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Application No. 08/994,878
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5. A method for obtaining and using a private key at user
equipment via a network, said method comprising:
transmitting from the user equipment an ID of a user;
receiving a private key of the user encrypted with a user
identifying key associated with the user; and
decrypting the encrypted private key using a user
identifying key determined from interaction with the user at the
user equipment;
using the decrypted private key; and
destroying or avoiding making any non-volatile record of the
private key at the location of the user.
The prior art references of record relied upon by the
examiner in rejecting the appealed claims are:
Asay et al. (Asay) 5,903,882 May 11, 1999
(filed Dec. 13, 1996)
Trostle 5,919,257 Jul. 06, 1999
(filed Aug. 08, 1997)
Bruce Schneier, Applied Cryptography 174 (2d ed., John Wiley
& Sons, Inc. 1996)(Schneier)
Claims 5 and 7 stand rejected under 35 U.S.C. § 103 as being
unpatentable over Trostle in view of Asay.
Claims 6 and 8 stand rejected under 35 U.S.C. § 103 as being
unpatentable over Trostle in view of Asay and Schneier.
Reference is made to the Examiner's Answer (Paper No. 28,
mailed April 7, 2003) for the examiner's complete reasoning in
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Application No. 08/994,878
3
support of the rejection, and to appellant's Brief (Paper No. 27,
filed February 10, 2003) for appellant's arguments thereagainst.
OPINION
As a preliminary matter, we note that on page 4 of the
Brief, appellant indicates that the claims are to stand or fall
together. In accordance therewith, appellant has presented no
separate arguments of patentability as to the dependent claims
nor the additional reference of Schneier for claims 6 and 8.
Therefore, we will treat the claims as a single group with claim
5 as representative. Appellant should note in accordance with
37 C.F.R. § 1.192(a) (which was in effect at the time of the
Brief) arguments not included in the brief are considered waived.
See also, In re Berger, 61 USPQ2d 1523, 1529 (Fed. Cir. 2002) and
Interactive Gift Express, Inc. v. Compuserve Inc., 256 F.3d 1323,
1344, 59 USPQ2d 1401, 1417 (Fed. Cir. 2001), in which the Federal
Circuit held that issues not raised in the Brief are waived.
We have carefully considered the claims, the applied prior
art references, and the respective positions articulated by
appellant and the examiner. As a consequence of our review, we
will affirm the obviousness rejections of claims 5 through 8.
Appeal No. 2003-1829
Application No. 08/994,878
4
Appellant argues (Brief, page 4) that Asay teaches storing
an encrypted copy of the user's key at the location of the user,
and, thus, Asay fails to teach the claim limitation of
"destroying, or avoiding making, any non-volatile record of the
private key at the location of the user." Appellant contends
that Asay "specifically teaches making, saving, and not
destroying at least one non-volatile record of the key." We
disagree.
Asay discloses (column 7, lines 46-50) a subscriber (or
user) "creating a standby application for certification of a new
key pair, digitally signing the standby application with a
private key and then destroying the private key" (emphasis ours).
Similarly, Asay states (column 30, lines 55-57) that the private
key is destroyed immediately after it is used to sign the standby
application. Thus, Asay explicitly teaches destroying the
private key at the user's terminal. Appellant argues (Brief,
page 5) that the passage in column 30 follows a statement that
the private key is stored in a safe place in the subscriber's
system, and therefore teaches away from the "claimed destruction
of any non-volatile record of the user's private key." However,
the claim recites an alternative of "destroying or avoiding
making" any non-volatile record of the private key. Although
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Application No. 08/994,878
5
Asay may initially store the private key on the user's system,
Asay clearly teaches destroying it after it is used, thereby
meeting the first claimed alternative.
Further, Asay teaches (column 27, lines 32-35) that
"technological improvements may render the security of the key
pair vulnerable to an attack facilitated by the availability of
an accumulating body of ciphertext." Similarly, Asay discusses
(column 28, lines 13-15) the risk of compromise of a private key.
Therefore, Asay clearly teaches the need to destroy the private
key so as to avoid rendering it vulnerable to an attack or to
risk of compromise. Consequently, we find appellant's argument
unpersuasive. Appellant has not argued the combinability of the
references, nor presented any further arguments. Therefore, we
will sustain the rejection of claims 5 through 8.
CONCLUSION
The decision of the examiner rejecting claims 5 through 8
under 35 U.S.C. § 103 is affirmed.
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No time period for taking any subsequent action in
connection with this appeal may be extended under 37 C.F.R.
§ 1.136(a).
AFFIRMED
JAMES D. THOMAS )
Administrative Patent Judge )
)
)
)
) BOARD OF PATENT
ANITA PELLMAN GROSS ) APPEALS
Administrative Patent Judge ) AND
) INTERFERENCES
)
)
)
HOWARD B. BLANKENSHIP )
Administrative Patent Judge )
APG:clm
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Application No. 08/994,878
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