Ex Parte Chen et al

Patent Trial and Appeal Board

Apr 15, 2013

10769173 (P.T.A.B. Apr. 15, 2013)

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.
10/769,173 01/30/2004 Sherman (Xuemin) Chen 3875.0100000 7811
26111 7590 04/15/2013
STERNE, KESSLER, GOLDSTEIN & FOX P.L.L.C.
1100 NEW YORK AVENUE, N.W.
WASHINGTON, DC 20005
EXAMINER
PALIWAL, YOGESH
ART UNIT PAPER NUMBER
2435
MAIL DATE DELIVERY MODE
04/15/2013 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 SHERMAN CHEN and STEPHANE RODGERS
____________

Appeal 2010-008657
Application 10/769,173
Technology Center 2400
____________

Before DENISE M. POTHIER, BRUCE R. WINSOR, and
BARBARA A. BENOIT, Administrative Patent Judges.

POTHIER, Administrative Patent Judge.

DECISION ON APPEAL
STATEMENT OF THE CASE
Appellants appeal under 35 U.S.C. § 134(a) from the Examiner’s
rejection of claims 1-41. App. Br. 2.1 We have jurisdiction under 35 U.S.C.
§ 6(b). We affirm.

1 Throughout this opinion, we refer to the Appeal Brief (App. Br.) filed
November 18, 2009; (2) the Examiner’s Answer (Ans.) mailed February 18,
2010; and (3) the Reply Brief (Reply Br.) filed April 6, 2010.
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Invention
Appellants’ invention relates to a method and system for secure key
authentication. See Abstract. Claim 1 is reproduced below with certain
disputed limitations emphasized:
1. A method for secure key authentication, the method comprising:
generating at a first location a digital signature of a secure key to
obtain a digitally signed secure key;
encrypting the digitally signed secure key utilizing at least a
previously generated unreadable digitally signed and encrypted
secure key, wherein said previously generated unreadable digitally
signed and encrypted secure key was generated by encrypting a
previously generated digitally signed secure key; and
transmitting the digitally signed and encrypted secure key from the
first location.

The Examiner relies on the following as evidence of unpatentability:
Ellison US 6,073,237 June 6, 2000
Akiyama US 2002/0001386 A1 Jan. 3, 2002

The Rejection
Claims 1-41 are rejected under 35 U.S.C. § 103(a) as unpatentable
over Akiyama and Ellison. Ans. 3-10.

THE CONTENTIONS
Regarding illustrative claim 1, the Examiner finds that Akiyama
discloses encrypting a digitally-signed secure key using a previously
generated secure key (Ans. 3-4), but fails to teach the previously generated
secure key is encrypted and digitally signed and was generated by
encrypting a previously generated digitally-signed secure key (Ans. 4). For
these missing features, the Examiner discusses well known techniques for
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encrypting and digitally signing keys, including one discussed in Ellison.
Ans. 4-5.
Appellants argue Akiyama does not disclose or teach the work keys
are encrypted using previously generated work keys (App. Br. 8). Pointing
to ¶¶ 46-54 in the Specification and Figure 6A, Appellants further assert that
the secure key (e.g., output) and the key that encrypts the secure key (e.g., an
input) must be the same type (e.g., both are work or scrambling keys). App.
Br. 9-10, 14; Reply Br. 5-6, 9-10.
Regarding illustrative claim 7, Appellants argue that Akiyama fails to
teach its recited feature of “if the secure key comprises a scrambling key,
then a decrypted digitally signed work key at the second location is utilized
for decrypting an encrypted digitally signed scrambling key.” App. Br. 16-
17. Appellants assert that the contract information in Akiyama only
discloses a work key and not a scrambling key and also fails to disclose the
work key is used to decrypt the scrambling key. App. Br. 17.

ISSUES
(1) Under § 103, has the Examiner erred in rejecting claim 1 by
finding that Akiyama and Ellison would have taught or suggested “the
digitally signed secure key” and the “at least a previously generated
unreadable digitally signed and encrypted secure key,” giving these terms
their broadest reasonable interpretation in light of the Specification?
(2) Under § 103, has the Examiner erred by finding that Akiyama and
Ellison collectively would have taught or suggested, if the secure key
comprises a scrambling key, then a decrypted digitally signed work key at
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the second location is utilized for decrypting an encrypted digitally signed
scrambling key as recited in claim 7?

ANALYSIS
Claims 1-6, 8-16, 18-26, 28-37, and 39-41
Based on the record before us, we find no error in the Examiner’s
rejection of illustrative claim 1, which calls for encrypting the digitally
signed secure key using at least a previously generated unreadable digitally
signed and encrypted secure key and the previously generated unreadable
digitally signed and encrypted secure key is generated by encrypting a
previously signed secure key. This claim recites three keys (e.g., the
digitally signed secure key to be encrypted, the previously generated
unreadable digitally signed and encrypted secure key used to encrypt the
digitally signed secure key, and a previously generated digitally signed
secure key used to generate the previously generated unreadable digitally
signed and encrypted secure key). Even so, as broadly as reasonably
construed, each of these keys is no more than a “secure” key. Thus, these
keys are required to be “secure” keys. However, we agree with the
Examiner (see Ans. 11-12) that these recitations do not require the keys to
be same type, such as all being “work” or “master” keys.
Appellants point to ¶¶ 46-54 in the disclosure and Figure 6A to
support their position that the recited keys must be same type. App.
Br. 9-10, 13-14 (reproducing Fig. 6A and citing the accompanying
description); Reply Br. 5-6, 8-9. Namely, Appellants argue that digitally
signed secure keys 638 (described as an input) must be the same type as the
encrypted and signed secure key 632 (described as an output), because the
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encrypted and signed secure keys 632 are looped back to the encryptor 608
for encrypting digitally signed secure keys 638, and “[o]bviously, the
digitally signed secure keys and the encrypted digitally signed secure keys
are of the same type.” App. Br. 10. We are not persuaded.
First, we will not import a particular embodiment or example in
disclosure (e.g., Fig. 6A and its discussion) into a claim limitation where, as
is here, the claim recitations are broader in scope. See SuperGuide Corp. v.
DirecTV Enters., Inc., 358 F.3d 870, 875 (Fed. Cir. 2004). That is, there is
nothing in the claim 1, as discussed above, that limits the “secure” keys to be
of the same type, such as both being work or scrambling keys. Moreover,
Appellants have not defined (see generally Spec.) or adequately
demonstrated that an ordinarily skilled artisan would have understood the
recited phrase, “secure key” to be of the same type (see App. Br. 9-14; Reply
Br. 5-9), such that the Examiner’s broad claim construction is unreasonable.
Second, the disclosure itself does not limit the secure keys (e.g., the
digitally signed secure key and the previously generated unreadable digitally
signed and encrypted secure key) to a particular type. See Ans. 12 (citing
Spec. ¶ 28, which indicates “[t]he secure key may be a master key, a work
key and/or a scrambling key”); see also Ans. 13. Claim 4 also recites that
the secure key can be at least one of three types (i.e., a master, work, and
scrambling). However, there is no discussion that both the signed secure
key (e.g., 638) and encrypted and signed keys (e.g., 628, 630, 632) are the
same type (e.g., master, work, scrambling). See Spec. ¶¶ 46-54.
Third, we disagree with Appellants’ position that “[o]bviously, the
digitally signed secure keys and the encrypted digitally signed secure keys
are of the same type” because they are both feed into encryptor 608. See
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App. Br. 10. In fact, ¶ 47, cited by Appellants (App. Br. 12), describes
master keys 618 can be used to encrypt “one of more secure keys, for
example, a work key and/or a scrambling key.” See Spec. ¶ 47. These
master keys 618 are enhanced and used to generate secure master keys 624,
626, which may be feed into encryptor 608 to encrypt the signed secure keys
received at encryptor 608. See Spec. ¶¶ 49, 51, 53; Fig. 6A. Given that a
secure key can be any or a combination of a master, work, and/or scrambling
key (see Spec. ¶ 28), Appellants discuss a scenarios where a different type of
key (e.g., master secure key 624) is used by encryptor 608 to encrypt a
different type of signed secure key 638 (e.g., a work secure key).
Like the Examiner (Ans. 14), we find Appellants have not sufficiently
demonstrated that the recited secure key and key that encrypts the secure key
must be or are obviously the same type because they are both fed through
encryptor 608. See App. Br. 9-10, 14. It is well settled that arguments of
counsel cannot take the place of factually supported objective evidence. See
In re Huang, 100 F.3d 135, 139-40 (Fed. Cir. 1996). We thus find the
arguments that the “secure” keys must be the same type are not
commensurate in scope with claim 1’s limitations.
Accordingly, the prior art need only teach the recited digitally signed
secure key is encrypted using at previously generated digitally signed and
encrypted secure key. We are not persuaded by Appellants’ argument that
Akiyama’s master key, along with Ellison’s teaching, cannot be mapped to
the recited digitally signed secure key and the previously generated
unreadable digitally signed and encrypted secure key as recited because
these mapped secure keys are not disclosed or taught to be of same master,
work, or scrambling type. See App. Br. 7-8. Based on the record and the
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Examiner’s undisputed findings in this regard (Ans. 3-5, 11-12), the
references collectively teach encrypting a digitally signed secure key using a
previously generated unreadable digitally signed and encrypted secure key,
wherein the previously generated unreadable digitally signed and encrypted
secure key was generated by encrypting a previously generated digitally
signed secure key as recited in claim 1.
Lastly, we consider any additional reasons for allowability of the
dependent claims held in reserve waived. See App. Br. 15-16, 18-19.
For the foregoing reasons, Appellants have not persuaded us of error
in the rejection of independent claim 1 and claims 2-6, 8-16, 18-26, 28-37,
and 39-41 not separately argued with particularity (App. Br. 15-16, 18-19).

Claims 7, 17, 27, and 38
We also find no error in the Examiner’s rejection of illustrative claim
7. Claim 7 additionally recites that, if the secure key comprises a scrambling
key, then a decrypted digitally signed work key at the second location is
utilized for decrypting an encrypted digitally signed scrambling key.
Appellants argue that the contract information in Akiyama only discloses a
work key and not a scrambling key and also fails to disclose the work key is
used to decrypt the scrambling key. App. Br. 17.
The Examiner explains that the channel key, Kch, discussed in
Akiyama is mapped to the recited secure key that is an encrypted scrambling
key and the acquired work key is mapped to the recited decrypted work key
used to decrypt the scrambling key (e.g., decrypted information in the
common control packet that contains the channel key). Ans. 7, 19 (citing
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Akiyama ¶ 0125). The Examiner additionally discusses Ellison to address
the “digitally signed” limitations in the claim. See Ans. 7, 19.
We find this position reasonable. While Appellants argue that ¶ 0125
does not teach the contract information in Figure 5 includes a scrambling
key (App. Br. 17), the Examiner has explained how the discussed encrypted
control packet, which includes the enciphered contract information (see Ans.
3-4 (citing Akiyama ¶ 0106; Fig. 7)), contains a scrambling key. See Ans.
19. The Examiner also states that the scrambling key (i.e., channel key Kch)
is acquired from the decrypted information, which includes the scrambling
key, by using a work key. See id.
We also refer to our previous discussion for any arguments presented
for claim 7 related to the arguments made concerning claim 1. App. Br. 16.
Moreover, we consider any additional reasons for allowability of claim 7
held in reserve waived. See id.
For the foregoing reasons, Appellants have not persuaded us of error
in the rejection of claim 7 and claims 17, 27, and 38 not separately argued
with particularity (App. Br. 16-17).

CONCLUSION
The Examiner did not err in rejecting claims 1-41 under § 103.

DECISION
The Examiner’s decision rejecting claims 1-41 is affirmed.
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).

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AFFIRMED

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