Ex Parte Rodgers et alDownload PDFPatent Trial and Appeal BoardMay 19, 201511743533 (P.T.A.B. May. 19, 2015) Copy Citation 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. 11/743,533 05/02/2007 Stephane Rodgers 3875.1520002 7035 26111 7590 05/19/2015 STERNE, KESSLER, GOLDSTEIN & FOX P.L.L.C. 1100 NEW YORK AVENUE, N.W. WASHINGTON, DC 20005 EXAMINER HERZOG, MADHURI R ART UNIT PAPER NUMBER 2438 MAIL DATE DELIVERY MODE 05/19/2015 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 STEPHANE RODGERS and ANDREW DELLOW ____________ Appeal 2013-002837 Application 11/743,533 Technology Center 2400 ____________ Before THOMAS L. GIANNETTI, JEFFREY A. STEPHENS, and JESSICA C. KAISER, Administrative Patent Judges. KAISER, Administrative Patent Judge. DECISION ON APPEAL Appellants appeal under 35 U.S.C. § 134(a) from the Examiner’s Final Rejection of claims 1, 3–15, and 17–30, all of the claims pending in the Application. We have jurisdiction under 35 U.S.C. § 6(b). We reverse. Appeal 2013-002837 Application 11/743,533 2 EXEMPLARY CLAIMS Exemplary claims 1 and 12 are reproduced below (emphasis added): 1. A method for signal processing, the method comprising: in a secure communication system in an integrated circuit: receiving an encrypted transport stream; decrypting said transport stream; extracting from said decrypted transport stream, a command for revoking a secure key, wherein said secure key is encrypted; decrypting said command for revoking said secure key utilizing a hidden key; verifying a signature of said decrypted command for revoking said secure key; and revoking said secure key upon successful verification of said signature. 12. A method for signal processing in a secure communication system, the method comprising: generating a command for revoking a secure key, wherein said secure key is encrypted, said command for transmission to a secure communication system in an integrated circuit; encrypting said generated command for revoking said secure key utilizing a hidden key; signing said encrypted generated command for revoking said secure key; combining said signed and encrypted generated command with video data being transmitted to said secure communication system in an integrated circuit; and encrypting said combined video data and signed and encrypted generated command. Appeal 2013-002837 Application 11/743,533 3 REJECTIONS AT ISSUE The Examiner rejected claims 1, 4, 5, 10–15, 18, 19, and 24–30 under 35 U.S.C. § 103(a) as being unpatentable over the combination of Hunt (US 2005/0123135 Al; published June 9, 2005) and Murase (US 2002/0126843 Al; published Sept. 12, 2002). (Final Act. 4–15; Ans. 3–14.) The Examiner rejected claims 3, 6–9, 17, and 20–23 under 35 U.S.C. § 103(a) as being unpatentable over the combination of Hunt, Murase, and additional references. (Final Act. 15–17; Ans. 14–16.) ISSUES The dispositive issues presented by Appellants’ arguments are: Did the Examiner provide sufficient reasoning with some rational underpinning to support “verifying a signature of said decrypted command for revoking said secure key,” as recited in claim 1, would have been obvious from Hunt’s teachings? Did the Examiner provide sufficient reasoning with some rational underpinning to support “signing said encrypted generated command for revoking said secure key” and “encrypting said combined video data and signed and encrypted generated command,” as recited in claim 12, would have been obvious from Hunt’s teachings? ANALYSIS Obviousness Rejections of Claims 1, 3–11, 15, and 17–25 Appellants argue Hunt and Murase, alone or in combination, do not teach or suggest “verifying a signature of said decrypted command for revoking said secure key,” as recited in claim 1. (App. Br. 10–11.) The Appeal 2013-002837 Application 11/743,533 4 Examiner finds “Hunt teaches verification of signature of the encrypted command instead of the decrypted command.” (Final Act. 6 (citing Hunt Fig 3, ¶ 61) (emphasis added); see also Ans. 17.) 1 The Examiner finds “verifying the signature of the command prior to decrypting the command instead of verifying the signature after decrypting the command is an obvious variation and would have yielded predictable results to one of ordinary skill in the art at the time of the invention.” (Final Act. 6.) Appellants argue the Examiner’s rationale is conclusory, rather than articulated reasoning with some rational underpinning necessary to support an obviousness conclusion. (App. Br. 11.) We agree with Appellants. The Examiner finds modifying Hunt to verify the signature of a decrypted command would have been obvious because “the substitution of one known element (verifying signature after decryption of command) for another (verifying signature . . . before decryption of command) would have yielded predictable results (verifying signature of the received revocation command) to one of ordinary skill in the art at the time of the invention.” (Ans. 17–18.) The Examiner, however, has not shown that “verifying signature after decryption of command” was a known variation because the cited portions of Hunt teach only verifying the signature before decryption. The Examiner also finds “the signature [in Hunt] is based on ‘N,REVOKE,model,rev’ and not the encrypted parameters. When the encrypted revocation message is decrypted, the parameters that are obtained are ‘N,REVOKE,model,rev.’ Therefore, the signature is based on unencrypted parameters that are the same as the decrypted parameters.” 1 The Examiner does not rely on Murase as teaching the contested limitation. (Final Act. 6–7.) Appeal 2013-002837 Application 11/743,533 5 (Ans. 17.) Appellants argue “[t]hese statements are mere conjecture and are not supported by the applied sections of Hunt.” (Reply Br. 2–3.) We agree with Appellants. Hunt teaches use of a key to validate the signature of an encrypted message and use of a key to decrypt that message. (Hunt ¶ 59 (“A revocation message . . . may comprise information in the form of: ESRE[model](N,REVOKE,model,rev) SSR[n]"(N,REVOKE,model,rev) . . . .”), ¶ 61 (“At step 306, the SVG hardware authenticates the signature of the message using its SSR[n]" key.”), ¶ 62 (“If the message signature is valid at step 308, then the SVG hardware may decrypt the message using its ESRE[model] key at step 312.”).) Hunt further teaches those keys are both for a message with parameters N,REVOKE,model,rev. (Hunt ¶ 41 (“Given a message ‘m,’ [then] ‘c=EK(m)’ represents the cyphertext of m produced by symmetric encryption with the secret key K . . . . Also, ‘s=SK"(m)’ represents the digital signature of ‘m,’ using the private key K" . . . .”).) In other words, Hunt teaches that the key for verifying the signature and the key for decrypting the message relate to the same message (i.e., the message with parameters N,REVOKE,model,rev). The cited portions of Hunt, however, do not teach that the signature itself is based on those parameters or that the signature is based only on unencrypted parameters, as the Examiner finds. The Examiner has the initial burden of presenting a prima facie case of unpatentability. In re Oetiker, 977 F.2d 1443, 1445 (Fed. Cir. 1992). Because the Examiner has not provided sufficient articulated reasoning with some rational underpinning to support that “verifying a signature of said decrypted command for revoking said secure key,” as recited in claim 1, would have been obvious, the Examiner has not met that initial burden. Appeal 2013-002837 Application 11/743,533 6 Accordingly, we reverse the Examiner’s obviousness rejection of independent claim 1, independent claim 15 which recites a similar limitation, and claims 4, 5, 10, 11, 18, 19, 24, and 25, which depend from claims 1 or 15. Claims 3, 6–9, 17, and 20–23 depend directly or indirectly from claim 1 or claim 15. The additional references as applied by the Examiner in rejecting those claims are not shown to cure the deficiencies discussed supra. Accordingly, we reverse the rejections of those claims for the same reasons as claim 1. Obviousness Rejection of Claims 12–14 and 26–30 Appellants argue “the generation of the revocation message is done in a particular manner as recited in claims 12 and 26, none of is [sic] taught or suggested by Hunt.” (App. Br. 14; see also id. at 17.) The Examiner finds “Hunt teaches receiving a revocation message from a public server or an upstream media or device but does not explicitly teach the generation of the revocation message.” (Final Act. 12.) 2 The Examiner finds “it would have been obvious . . . that if a revocation message of the format shown in para [0059] [of Hunt] is received by the player/receiver, then the revocation message has to be first generated and then sent to the player/receiver to be received by the player/receiver.” (Id. at 12–13.) Appellants argue Hunt’s receipt and processing of a signed, encrypted revocation command does not teach “signing said encrypted generated command for revoking said secure key” or “encrypting said combined video 2 The Examiner does not rely on Murase as teaching generating a revocation message or processing such a message, as recited in claim 12. (Id.) Appeal 2013-002837 Application 11/743,533 7 data and signed and encrypted generated command,” as recited in claim 12. (App. Br. 15–17.) 3 The Examiner finds Hunt teaches receipt of an encrypted, signed revocation command embedded in encrypted video data (i.e., secure video content or SVC), and thus it would have been obvious that such a message was first generated. (See Ans. 20–25.) We agree with the Examiner (Final Act. 12–13) that if a revocation command is received as taught in Hunt, such a command must have been generated. Nevertheless, we find the Examiner has not articulated sufficient reasoning with some rationale underpinning explaining why it would have been obvious to perform the other steps recited in claim 12 in the manner claimed. Specifically, the Examiner finds “the encrypted revocation message is signed [in Hunt] before it is transmitted to the player/receiver” (Ans. 23), but has not adequately explained why it would have been obvious to sign the encrypted command, as recited in claim 12, rather than to sign the unencrypted command. The Examiner also finds Hunt teaches detecting an encrypted revocation message embedded in encrypted video data (Ans. 23–25), but has not adequately explained why it would have been obvious to encrypt the combined video data and command, as recited in claim 12, rather than encrypt them separately prior to combination. Thus, we find the Examiner has not presented a prima facie case of obviousness. Accordingly, we reverse the Examiner’s obviousness rejection of independent claim 12, independent claim 26 containing limitations 3 Appellants address these arguments to limitations of independent claim 26 (id.), and we find these arguments apply equally to the substantially similar limitations of independent claim 12. Appeal 2013-002837 Application 11/743,533 8 commensurate in scope with claim 12, and claims 13, 14, and 27–30, which depend from claim 12 or claim 26. DECISION We reverse the Examiner’s § 103 rejections of claims 1, 3–15, and 17–30. REVERSED ACP Copy with citationCopy as parenthetical citation