Ex Parte Drehmel et al

Patent Trial and Appeal BoardNov 28, 2012

10892430 (P.T.A.B. Nov. 28, 2012)

UNITED STATES PATENT AND TRADEMARK OFFICE ____________________ BEFORE THE PATENT TRIAL AND APPEAL BOARD ____________________ Ex parte ROBERT A. DREHMEL, WILLIAM E. HALL, and RUSSELL D. HOOVER ____________________ Appeal 2009-012903 Application 10/892,430 Technology Center 2400 ____________________ Before CARL W. WHITEHEAD, JR., ERIC S. FRAHM, and ANDREW J. DILLON, Administrative Patent Judges. FRAHM, Administrative Patent Judge. DECISION ON APPEAL Appeal 2009-012903 Application 10/892,430 2 STATEMENT OF THE CASE Introduction Appellants appeal under 35 U.S.C. § 134(a) from a final rejection of claims 1, 4-7, and 9-11, all the claims pending in the application. Claims 2, 3, 8, and 12-21 have been canceled. We have jurisdiction under 35 U.S.C. § 6(b). We affirm. Appellants’ Disclosed Invention Appellants disclose and claim a method of handling secure data passed between a processor and a memory external to the processor that keeps integrity check values internal to the system on a chip (SOC) in order to prevent attacks (Spec. ¶¶ [0001]-[0006]; Abs.; claims 1 and 9). Exemplary Claim An understanding of the invention can be derived from a reading of exemplary claim 1, which is reproduced below: 1. A method of handling secure data passed between a processor and memory external to the processor, comprising: receiving a secure block of data to be written to the memory external to the processor; generating, by the processor, a first integrity check value as a function of the received secure block of data; encrypting, by the processor, the secure block of data; generating, by the processor, a second integrity check value as a function of the encrypted secure block of data; generating, by the processor, a third integrity check value as a function of the first integrity check and the second integrity check; Appeal 2009-012903 Application 10/892,430 3 storing the secure block of data, in encrypted form, in the memory external to the processor; and storing the first integrity check value in memory internal to the processor. The Examiner’s Rejections (1) The Examiner rejected claims 1, 5-7, and 9 under 35 U.S.C. § 103(a) as being unpatentable over the combination of Windel (US 5,805,711) and Geiringer (US 2004/0076291 A1). Ans. 3-5. (2) The Examiner rejected claim 4 under 35 U.S.C. § 103(a) as being unpatentable over the combination of Windel, Geiringer, and Van Meter (US 6,964,008 B1). Ans. 6. (3) The Examiner rejected claims 10 and 11 under 35 U.S.C. § 103(a) as being unpatentable over the combination of Windel, Geiringer, and Tune (US 7,149,862 B2). Ans. 6-7. Appellants’ Contentions1 Appellants contend (Br. 10-12) that the Examiner erred in rejecting claims 1, 5-7, and 9 under 35 U.S.C. § 103(a) as being unpatentable over the combination of Windel and Geiringer for numerous reasons, including: (1) although Windel receives a MAC or integrity check value in a processor and stores it in a RAM that is internal to the processor, Windel only encrypts the MAC value, in contrast to what is recited in claims 1 and 9 (Br. 11-12); (2) Windel’s MAC is not equivalent to the “integrity check value” recited in claims 1 and 9 (Br. 11); (3) Windel fails to disclose encrypting the secure block of data using 1 Appellants do not provide separate patentability arguments for claims 5 and 7. Appeal 2009-012903 Application 10/892,430 4 the processor (Br. 11-12); and (4) Windel fails to disclose storing the secure block of data in encrypted form in the memory external to the processor (Br. 12). Appellants also argue that claims 4, 10, and 11, rejected under combinations with additional references, are patentable for the same reasons already argued with respect to independent claims 1 and 9 rejected over the combination of Windel and Geiringer (Br. 12). Principal Issue on Appeal Based on Appellants’ arguments in the Brief, the dispositive issue presented on appeal is: Did the Examiner err in rejecting claims 1, 4-7, and 9-11 under 35 U.S.C. § 103(a) as being unpatentable over the various combinations of references because Windel fails to teach or suggest an “integrity check value” that is a function of a “received a secure block of data,” encrypting the secure block of data, and “storing the secure block of data, in encrypted form, in the memory external to the processor,” as recited in independent claims 1 and 9? ANALYSIS We have reviewed the Examiner’s rejections in light of Appellants’ contention in the Appeal Brief (Br. 10-12) that the Examiner has erred and we disagree with the Appellants’ conclusions. We adopt as our own (1) the findings and reasons set forth by the Examiner in the action from which this appeal is taken and (2) the reasons set forth by the Examiner in the Examiner’s Answer in response to the Appellants’ Appeal Brief (Ans. 3-7). We highlight and amplify certain teachings and suggestions of Windel as follows. Appeal 2009-012903 Application 10/892,430 5 Windel discloses encrypting “security-associated data” (col. 7, ll. 63- 65) and storing the security-associated data externally (col. 8, ll. 8-15). Windel also discloses (see col. 10, ll. 11-13; col. 13, ll. 33-52) a message authentification code (MAC) value that is sent to an internal memory and used to form a cryptographic checksum relating to content in the external memory that “is stored in a non-volatile memory area (block 71) of the external program memory of the microprocessor system” (col. 13, ll. 50-52). Windel’s method “only allows a read-out of the program code and the data in encrypted form” (col. 11, ll. 41-42) and provides secure cryptographic functions “with a secret code that is hidden unreadably in the internal program memory” (col. 13, ll. 38-39). Appellants’ arguments (Br. 10-12) that Windel’s MAC described in columns 6, 8, and 10 is not an “integrity check value” as recited in claims 1 and 9 are not persuasive in light of the Examiner’s reliance on Windel’s checksum from data stored in an external memory shown in Figures 3, 4, 6, and 7 and described in column 10, lines 32-40; column 12, lines 1-9 and 41- 47; and column 13, lines 26-29 for this feature. Appellants’ arguments (Br. 11-12) that Windel fails to disclose using a processor to encrypt a secure block of data and then storing the encrypted secure block of data in a memory external to the processor are also unpersuasive because Appellants have failed to address the Examiner’s citations (Ans. 7) to column 7, lines 63-65; column 11, lines 30-41; and column 13, lines 33-50 describing Figures 6 and 7. These portions of Windel are persuasive that this feature is also met, especially column 11, lines 38-42 and column 13, lines 33-48. Appeal 2009-012903 Application 10/892,430 6 We do not find Appellants’ arguments to be persuasive in light of the Examiner’s findings. Appellants’ arguments do not address the specific findings of the Examiner in relation to the rejection of claims 1 and 9. Once the Examiner has satisfied the burden of presenting a prima facie case of obviousness, the burden then shifts to Appellants to present evidence and/or arguments that persuasively rebut the Examiner’s prima facie case. See In re Oetiker, 977 F.2d 1443, 1445 (Fed. Cir. 1992). Since Appellants do not particularly point out errors in the Examiner’s reasoning to persuasively rebut the Examiner’s prima facie case of obviousness, the rejection of claims 1 and 9 is sustained. For the above reasons, we are also affirming the rejections of dependent claims 5-7 whose merits are not separately argued. In re Nielson, 816 F.2d 1567, 1572 (Fed. Cir. 1987). We will also sustain the rejection of (i) claim 4 for the reasons stated in connection with claim 1 and (ii) claims 10 and 11 for the reasons stated in connection with claim 9. CONCLUSIONS (1) The Examiner did not err in rejecting claims 1, 5-7, and 9 as being unpatentable under 35 U.S.C. § 103(a) over the combination of Windel and Geiringer because Windel teaches or suggests an “integrity check value” that is a function of a “received secure block of data,” encrypting the secure block of data, and “storing the secure block of data, in encrypted form, in the memory external to the processor,” as recited in claims 1 and 9. (2) The Examiner did not err in rejecting claims 4, 10, and 11 as being unpatentable under 35 U.S.C. § 103(a) over the combination of Windel and Geiringer in view of additional references for the reasons discussed in connection with claims 1 and 9. Appeal 2009-012903 Application 10/892,430 7 DECISION The Examiner’s rejections of claims 1, 4-7, and 9-11 are 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). AFFIRMED peb