Ex Parte Iyengar et al

Patent Trial and Appeal Board

Feb 23, 2015

11734315 (P.T.A.B. Feb. 23, 2015)

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.
11/734,315 04/12/2007 Arun Kwangil Iyengar YOR920070055US1 9800
48063 7590 02/23/2015
RYAN, MASON & LEWIS, LLP
48 South Service Road
Suite 100
Melville, NY 11747
EXAMINER
POPHAM, JEFFREY D
ART UNIT PAPER NUMBER
2491
MAIL DATE DELIVERY MODE
02/23/2015 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 PATENT TRIAL AND APPEAL BOARD
____________________

Ex parte ARUN KWANGIL IYENGAR, MUDHAKAR SRIVASTAVA,
and JIAN YIN

Appeal 2012-010434
1

Application 11/734,315
Technology Center 2400
____________________

Before JEAN R. HOMERE, CARL W. WHITEHEAD JR, and
JOHNNY A. KUMAR, Administrative Patent Judges.

HOMERE, Administrative Patent Judge.

DECISION ON APPEAL

1
Appellants identify the real party in interest as International Business
Machines Corp. App. Br. 1.
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Application 11/734,315

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STATEMENT OF THE CASE
Appellants appeal under 35 U.S.C. § 134(a) from the Examiner’s
Final Rejection of claims 1–21. App. Br. 2. We have jurisdiction under 35
U.S.C. § 6(b).
We AFFIRM.
Appellants’ Invention
Appellants invented a method and system for providing temporal
access control to secure broadcast services in a client-server environment.
Spec. 1:5–8. In particular, upon obtaining from the broadcast service
provider an authorization key for a specific time interval, a client device
derives a decryption key from the authentication key to decrypt a received
message previously encrypted by the service provider using an encryption
key derived from the authorization key. Spec. 4:13–20 Consequently, the
derived decryption key is able to decrypt the encrypted message provided
that the time limit of the decryption key matches that of the encrypted key,
and is within the time interval of the authorization key. Id. .
Representative Claim
Independent claim 1 is representative. It reads as follows:

1. In a client-server system, a method for providing access
control, comprising the steps of:
generating keys using a hierarchical time-based
key generation process;
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a client device obtaining an authorization key for
a time interval [a, b];
a server device deriving an encryption key
corresponding to a given time t and using said
encryption key to encrypt a message; and
the client device deriving, from the obtained
authorization key, a decryption key corresponding to
the given time t if (a < t < b) and decrypting the
message.
Prior Art Relied Upon

Benaloh US 7,069,450 B2 Jun. 27, 2006
Saarikivi US 2007/0201695 A1 Aug. 30, 2007
Asano US 7,319,752 B2 Jan. 15, 2008
Bohm US 7,581,108 B1 Aug. 25, 2009

Rejections on Appeal
The Examiner rejects the claims on appeal as follows:
Claims 1–6, 8–15, and 17–21 stand rejected under 35 U.S.C. § 103(a)
as being unpatentable over the combination of Saarikivi, Asano, and Bohm.
Claims 7 and 16 stand rejected under 35 U.S.C. § 103(a) as being
unpatentable over the combination of Saarikivi, Asano, Bohm, and Benaloh.

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ANALYSIS
We consider Appellants’ arguments seriatim as they are presented in
the Appeal Brief, pages 6–12.
2

Dispositive Issue: Under 35 U.S.C. § 103, did the Examiner err in
finding the combination of Saarikivi, Asano, and Bohm teaches or suggests
a client device deriving a decryption key from an authorization key to
decrypt an encrypted message, wherein the decryption key and the
corresponding encryption key have the same time limit, which falls within
the time period for which the authorization key was granted, as recited in
claim 1?
Appellants argue the proffered combination of references does not
teach or suggest the disputed limitations emphasized above. App. Br. 6–11.
We have reviewed the Examiner’s rejection in light of Appellants’
arguments. We are unpersuaded by Appellants’ contentions. We adopt as
our own the findings and reasons set forth by the Examiner in the action
from which this appeal is taken, and as detailed in the Examiner’s Answer in
response to Appellants’ Appeal Brief. See Ans. 12–20. However, we

2
Rather than reiterate the arguments of Appellants and the Examiner, we
refer to the Appeal Brief (filed February 24, 2012), and the Answer (mailed
April 17, 2012) for the respective details. We have considered in this
decision only those arguments Appellants actually raised in the Brief. Any
other arguments Appellants could have made but chose not to make in the
Briefs are deemed to be waived. See 37 C.F.R. § 41.37(c)(1)(vii).
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highlight and address specific arguments and findings for emphasis as
follows.
First, Appellants argue Asano discloses using block keys to encrypt
block data, but not to decrypt the block data. App. Br. 7. This argument is
not persuasive. We agree with the Examiner that because Appellants have
not addressed in the Brief the finding made in the Final Rejection and in the
Answer (Ans. 5) that the portions of Saarikivi relied upon teach deriving a
decryption key having the same time as the encryption key, the only
disputed fact at issue in this appeal is whether Asano teaches a client device
deriving the decrypted key from the authorization key. Ans. 13. Further, we
agree with the Examiner Asano’s disclosure of generating a block key to
encrypt block data, and to decrypt block data (Asano col. 42:19–21, Fig. 32)
teaches at least the decrypted key is derived from a generated block key.
Ans. 14.
Second, Appellants argue that even if Asano taught using the same
authentication data to generate the decryption key and the encryption key, as
proffered by the Examiner, such teaching would not meet the claim
limitations because the claim does not require deriving the decryption key
from the same data the encryption key was generated. App. Br. 8.
Therefore, Appellants submit the Examiner is improperly reading limitations
from the Specification into the claim. Id. 8–10. This argument is
unavailing. We agree with the Examiner that because the claim does not
impose any limitation upon the encryption key derivation, the claim does not
preclude such key derivation from being obtained from the authorization
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key. Ans. 17–20. Therefore, the disputed limitations can be broadly and
reasonably construed as deriving both the encryption key and the decryption
key from the same authorization. Accordingly, we concur with the
Examiner’s finding that Asano’s teaching of both the encryption/decryption
keys being derived from the block data key would complement Saarikivi’s
teaching of the encryption/decryption keys being valid for the time period of
the authentication key to thereby teach the disputed limitations. Id.
Regarding the rejection of claims 2–21, because Appellants have not
presented separate patentability arguments or have reiterated substantially
the same arguments as those previously discussed for patentability of claim
1 above, claims 2–21 fall therewith. See 37 C.F.R. § 41.37(c)(1)(vii).
DECISION
We affirm the Examiner’s rejection of claims 1–21 as set forth above.
No time period for taking any subsequent action in connection with
this appeal may be extended under 37 C.F.R. § 1.136(a)(1)(iv).

AFFIRMED
rvb