Ex Parte Soliman

Board of Patent Appeals and Interferences

Jul 1, 2010

10387711 (B.P.A.I. Jul. 1, 2010)

UNITED STATES PATENT AND TRADEMARK OFFICE
UNITED STATES DEPARTMENT OF COMMERCE
United States Patent and Trademark Office
Address: COMMISSIONER FOR PATENTS
P.O. Box 1450
Alexandria, Virginia 22313-1450
www.uspto.gov
APPLICATION NO. FILING DATE FIRST NAMED INVENTOR ATTORNEY DOCKET NO. CONFIRMATION NO.
10/387,711 03/13/2003 Hamdy Soliman NMTECH13 7643
30996 7590 07/02/2010
ROBERT W. BECKER & ASSOCIATES
707 HIGHWAY 333
SUITE B
TIJERAS, NM 87059-7507
EXAMINER
HENNING, MATTHEW T
ART UNIT PAPER NUMBER
2431
MAIL DATE DELIVERY MODE
07/02/2010 PAPER
Please find below and/or attached an Office communication concerning this application or proceeding.
The time period for reply, if any, is set in the attached communication.
PTOL-90A (Rev. 04/07)
UNITED STATES PATENT AND TRADEMARK OFFICE
____________

BEFORE THE BOARD OF PATENT APPEALS
AND INTERFERENCES
____________

Ex parte HAMDY SOLIMAN
____________

Appeal 2009-006119
Application 10/387,711
Technology Center 2400
____________

Before LEE E. BARRETT, LANCE LEONARD BARRY, and HOWARD
B. BLANKENSHIP, Administrative Patent Judges.

BARRY, Administrative Patent Judge.

DECISION ON APPEAL1

1 The two-month time period for filing an appeal or commencing a civil
action, as recited in 37 C.F.R. § 1.304, or for filing a request for rehearing,
as recited in 37 C.F.R. § 41.52, begins to run from the “MAIL DATE”
(paper delivery mode) or the “NOTIFICATION DATE” (electronic delivery
mode) shown on the PTOL-90A cover letter attached to this decision.

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Application 10/387,711

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STATEMENT OF THE CASE
The Patent Examiner rejected claims 1, 3, and 5-34. The Appellant
appeals therefrom under 35 U.S.C. § 134(a). We have jurisdiction under
35 U.S.C. § 6(b).

INVENTION
The Appellant describes the invention at issue on appeal as follows.
A dynamic computer system security method and system
using dynamic encryption and full synchronization between
system nodes. A data record from a data stream created by a
source user is encrypted with an initial dynamic session key. A
new dynamic session key is generated based upon a data record
and a previous dynamic session key. The new dynamic session
key is then used to encrypt the next data record. A central
authority is used to synchronize and authenticate both source
and destination users with dynamic authentication keys. The
central authority and users constantly regenerate new dynamic
authentication keys.
(Spec. 35.)

ILLUSTRATIVE CLAIMS
1. A method of providing a secure data stream between
system nodes, the method comprising:
providing a previous encryption key;
creating a data record at a source node, the data record
including plaintext to be exchanged;
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regenerating a new encryption key at the source node as a
function of the data record and a previous encryption key by
performing a logic operation on the previous encryption key
and the data record: and
performing a logic operation on the previous encryption
key and the data record to form an expanded key.

18. A method of authenticating one system node to
another system node, the method comprising the steps of:
generating an authentication key at a user node;
transmitting the authentication key to a central authority
node; and
starting a daemon at each of the user node and the central
authority node for continuously regenerating a new
authentication key and maintaining a corresponding number-
regeneration-counter at each of the user node and the central
authority node.

REJECTIONS
Claims 1, 3, and 5-17 stand rejected under 35 U.S.C. § 103(a) as
unpatentable over U.S. Patent No. 5,365,588 ("Bianco") and Applied
Cryptography ("Schneier").
Claims 18-24 and 27-29 stand rejected under 35 U.S.C. § 103(a) as
unpatentable over U.S. Patent No. 6,839,434 ("Mizikovsky") and U.S.
Patent Application No. 2003/0217292 ("Steiger").
Claim 25 stands rejected under 35 U.S.C. § 103(a) as unpatentable
over Mizikovsky; Steiger; and U.S. Patent No. 5,253,294 ("Maurer").
Claim 26 stands rejected under 35 U.S.C. § 103(a) as unpatentable
over Mizikovsky; Steiger; Maurer; and U.S. Patent No. 6,301,664 ("Di-
Crescenzo").
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Claims 30 and 33 stand rejected under 35 U.S.C. § 103(a) as
unpatentable over Mizikovsky; Steiger; and Operating System Concepts
("Silberschatz").
Claims 31, 32, and 34 stand rejected under 35 U.S.C. § 103(a) as
unpatentable over Mizikovsky; Steiger; Silberschatz and Handbook of
Applied Cryptography ("Menezes").

CLAIMS 1, 3, AND 5-17
The Examiner finds that "Schneier teaches that in one known method
of key generation, called cipher-feedback mode, the plaintext input is
encrypted with the 'previous encryption key', and the encrypted text is then
fed back into the key generation (See Schneier Page 200) . . . ." (Answer 4.)
The Appellant argues that "Schneier cannot be used to support a finding of
obviousness with respect to claim 1 because the teachings of Schneier are
antithetical to the recitations of claim 1." (Reply Br. 9.) Therefore, the issue
before us is whether the Examiner erred in finding that the combined
teachings of Bianco and Schneier would have suggested regenerating a new
encryption key at a source node as a function of a plaintext record and a
previous encryption key by performing a logic operation on the previous
encryption key and the plaintext as required by claim 1.

FINDINGS OF FACT
Bianco "relates to general purpose, high speed encryption
algorithms." (Col. 1, ll. 6-7.)
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The page of Schneier cited by the Examiner teaches that "[b]lock
ciphers can also be implemented as a self-synchronizing stream cipher; this
is called cipher-feedback (CFB) mode." (p. 200.)

ANALYSIS
"The Patent and Trademark Office (PTO) must consider all claim
limitations when determining patentability of an invention over the prior
art." In re Lowry, 32 F.3d 1579, 1582 (Fed. Cir. 1994) (citing In re Gulack,
703 F.2d 1381, 1385 (Fed. Cir. 1983)). Here, considering all the limitations
of independent claim 1, we agree with the Appellant's following
construction of the claim.
As clearly reflected in the language of claim 1, the data record
itself includes the plaintext to be exchanged, from which one
can readily infer that the step of regenerating the encryption key
is a function of a previous encryption key and, by substitution
of terms, the plaintext to be exchanged.
(Reply Br. 8.)
The question of obviousness is "based on underlying factual
determinations including . . . what th[e] prior art teaches explicitly and
inherently . . . ." In re Zurko, 258 F.3d 1379, 1383 (Fed. Cir. 2001). Here,
the Examiner admits that "Bianco did not specifically disclose regenerating a
new encryption key as a function of the data record and a previous
encryption key by performing a logic operation on the previous encryption
key and the data record." (Answer 4.) Because Bianco does not regenerate
a new encryption key at a source node as a function of any data record, the
same reference does not regenerate a new encryption key at a source node as
a function of a plaintext record.
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Turning to the second reference, we agree with the Examiner's
aforementioned finding that Schneier teaches that in the cipher-feedback
mode encrypted text is fed back into the key generation. The Examiner
concludes that "[i]t would have been obvious to the ordinary person skilled
in the art at the time of invention to employ the teachings of Schneier in the
encryption system of Bianco by feeding back the encrypted output into the
working register" (Answer 4) of the latter reference. Assuming arguendo
that such a modification would have been obvious and that the result would
have been operable, we are unpersuaded that the result would have
suggested the contested limitations of claim 1. To the contrary, we find that
the proposed modification would have regenerated a new encryption key at a
source node as a function of a ciphertext record and a previous encryption
key by performing a logic operation on the previous encryption key and the
ciphertext.
Based on the aforementioned facts and analysis, we conclude that the
Examiner erred in finding that the combined teachings of Bianco and
Schneier would have suggested regenerating a new encryption key at a
source node as a function of a plaintext record and a previous encryption key
by performing a logic operation on the previous encryption key and the
plaintext as required by claim 1 and claims 3 and 5-17, which depend
therefrom.

CLAIMS 18-33
Based on the Appellant's arguments, we will decide the appeal of
claims 18-33 based on claim 18 alone. The Examiner finds that Mizikovsky
teaches all of the limitations of claim 18 including that "[c]ol. 8 Lines 38-39
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of Mizikovsky discloses that the procedure of Mizikovsky, which includes
the generation of SSD [i.e., shared secret data key], is carried out
periodically, which falls within the scope of continuously." (Answer 18.)
He recognizes that the reference "does not specifically call his SSD
generation procedure a daemon." (Id.) The Examiner offers two
explanations to cure the omission.
The first explanation, which comprises several findings, follows.
[A] daemon, quite simply, is a program that performs a
housekeeping or maintenance utility function without being
called by the user. The periodicity of Mizikovsky is not due to
the procedure being called by a user, as can be seen in Col. 8
Lines 38-45. Further, reauthentication and regeneration of SSD
falls within the scope of a maintenance function. As such, the
SSD generation procedure of Mizikovsky basically reads on the
definition of a daemon.
(Id.)
The second explanation, which comprises a finding and a conclusion,
follows.
Steiger teaches that in a key updating system, a daemon
should be run on each of the nodes for maintaining the
synchronization of the keys (See Steiger Paragraph 0051).
It would have been obvious to the ordinary person skilled
in the art at the time of invention to employ the teachings of
Steiger in the periodic key updating system by running a
daemon on each node to perform the regenerating/
synchronization.
(Id. at 7.)
The Appellant argues that "Steiger . . . does not teach or disclose the use of
daemons for regenerating authentication keys between a user node and a
central authority node." (App. Br. 11.) Therefore, the issue before us is
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whether the Examiner erred in finding that the combined teachings of
Mizikovsky and Steiger, in combination with the knowledge of persons
skilled in the art, would have suggested using daemons to regenerate
authentication keys between a user node and a central authority node.

FINDINGS OF FACT
Mizikovsky "relates to . . . the updating of keys or other information
used by communicating parties." (Col. 1, ll. 8-10.) More specifically, the
reference "shows an embodiment of the key update and bidirectional
validation procedure between a wireless unit and the wireless
communications system." (Col. 7, ll. 5-7.) The key that is updated is
referred to as "a shared key (SSD)." (Id. at l. 9.)
Steiger "relates generally to network security . . . ." (¶ [0002], ll. 1-2.)
More specifically, the latter reference teaches that a "gatekeeper 430 may
take the form of a daemon operating on each of a plurality of import
servers 112 and serve to keep key information stored locally up to date and
substantially synchronized with other import servers 112." (¶ [0051], ll. 1-
4.)

ANALYSIS
"Non-obviousness cannot be established by attacking references
individually where the rejection is based upon the teachings of a
combination of references." In re Merck & Co., 800 F.2d 1091, 1097 (Fed.
Cir. 1986) (citing Keller, 642 F.2d at 425). "The test for obviousness is what
the combined teachings of the references would have suggested to one of
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ordinary skill in the art." In re Young, 927 F.2d 588, 591 (Fed. Cir. 1991)
(citing In re Keller, 642 F.2d 413, 425 (CCPA 1981)).
In determining obviousness, furthermore, a reference "must be read,
not in isolation, but for what it fairly teaches in combination with the prior
art as a whole." Id. "'Every patent application and reference relies to some
extent upon knowledge of persons skilled in the art to complement that
[which is] disclosed . . . .'" In re Bode, 550 F.2d 656, 660 (CCPA 1977)
(quoting In re Wiggins, 488 F.2d 538, 543 (CCPA 1973)). Those persons
"must be presumed to know something" about the art "apart from what the
references disclose." In re Jacoby, 309 F.2d 513, 516 (CCPA 1962).
Here, the Examiner's aforementioned finding that Mizikovsky teaches
continuously regenerating authentication keys between a user node and a
central authority node is uncontested. "Silence implies assent." Harper &
Row Publishers, Inc. v. Nation Enters., 471 U.S. 539, 572 (1985). His first
explanation, supra, is also uncontested. For our part, we agree with the
Examiner that persons skilled in the art would have known that a daemon is
a program that performs a housekeeping or maintenance utility function
without being called by the user. We also agree with him that column 8,
lines 38-45, of Mizikovsky supports his finding that the periodicity of the
reference's reauthentication is not based on manual activation. We agree
with the Examiner that Mizikovsky's reauthentication and regeneration of its
SSD key falls within the scope of a maintenance function. Therefore, we
agree with him that the reference's regeneration of its SSD is performed by a
daemon. The Appellant does not address, let alone show error in, these
findings.
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Second, the rejection is based on the combined teachings of
Mizikovsky and Steiger. As mentioned previously, the Examiner's finding
that Mizikovsky teaches continuously regenerating authentication keys
between a user node and a central authority node is uncontested. The
Appellant admits that "Steiger discloses the use of one or more daemons to
provide key maintenance at one or more import servers . . . ." (App. Br. 11.)
Therefore, we are persuaded that the combined teachings of Mizikovsky and
Steiger would have suggested using daemons to regenerate authentication
keys between a user node and a central authority node. Based on the
aforementioned facts and analysis, we conclude that the Examiner did not
err in finding that the combined teachings of Mizikovsky and Steiger, in
combination with the knowledge of persons skilled in the art, would have
suggested using daemons to regenerate authentication keys between a user
node and a central authority node.

CLAIM 34
The Examiner finds that "Mizikovsky further disclosed generating an
authentication key (SSD) based upon a previous authentication key
(RANDSSD)." (Ans. 20.) Besides reiterating the argument made for
claims 18-33, the Appellant argues that "Menenzes does not teach or
disclose the step of regenerating an authentication key based on a previous
authentication key at both the central authority node and the user node."
(App. Br. 17.) Therefore, the issue before us is whether the Examiner erred
in finding that the combined teachings of Mizikovsky and Steiger, in
combination with the knowledge of persons skilled in the art, would have
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suggested regenerating an authentication key based on a previous
authentication key at both a central authority node and a user node.

ANALYSIS
The rejection is based on the combined teachings of Mizikovsky,
Steiger, Silberschatz, and Menezes. As mentioned regarding claims 18-33,
the Examiner's finding that Mizikovsky teaches continuously regenerating
authentication keys between a user node and a central authority node is
uncontested. Likewise, his additional finding that "Mizikovsky further
disclosed generating an authentication key (SSD) based upon a previous
authentication key (RANDSSD)" (Ans. 20) is also uncontested. The
Appellant cannot establish non-obviousness by attacking Menezes
individually as lacking a limitation that the Examiner relies on Mizikovsky
to teach. Based on the aforementioned facts and analysis, we conclude that
the Examiner did not err in finding that the combined teachings of
Mizikovsky and Steiger, in combination with the knowledge of persons
skilled in the art, would have suggested regenerating an authentication key
based on a previous authentication key at both a central authority node and a
user node.

DECISION
We reverse the rejection of claims 1, 3, and 5-17. In contrast, we
affirm the rejections of claims 18-34.

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Application 10/387,711

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No time for taking any action connected with this appeal may be
extended under 37 C.F.R. § 1.136(a)(1). See 37 C.F.R. § 1.136(a)(1)(iv).

AFFIRMED-IN-PART

rwk

ROBERT W. BECKER & ASSOCIATES
707 HIGHWAY 333
SUITE B
TIJERAS NM 87059-7507