Ex parte Richards

• Decision Date: 15 May 2002
• Docket Number: 442,Application 08/810,Appeal 2000-1508
• Parties: Ex parte WILLIAM JAMES RICHARDS
• Court: Patent Trial and Appeal Board

Ex parte WILLIAM JAMES RICHARDS

Appeal No. 2000-1508

Application No. 08/810, 442

United States Patent and Trademark Office, Patent Trial and Appeal Board

May 15, 2002

This Opinion is Not binding Precedent of the Board.

ON BRIEF

Before BARRETT, DIXON, and BARRY, Administrative Patent Judges.

DECISION ON APPEAL

BARRY ADMINISTRATIVE PATENT JUDGE.

The examiner rejected claims 1-3, 5, 8, and 10. The appellant appeals therefrom under 35 U.S.C. § 134(a). We affirm-in-part.

BACKGROUND

The appellant's invention facilitates encryption and decryption in a cable television ("CATV") system. Analog CATV systems scramble programs and transmits the scrambled programs to customers. The customers are equipped with "set-top boxes" for unscrambling the programs.

Digital signal transmission, which possesses characteristics different from those of analog signal transmission, is coming into widespread use. The invention presents modes of encryption and decryption suited to the unique capabilities of digital signal transmission. Specifically, multiple decryption keys are used to decrypt encrypted material transmitted to customers of a CATV system. For example, a CATV broadcaster encrypts the movie "The Bells of St Mary's" using a segment key ("SK"). The broadcaster then encrypts the SK using a program key ("PK") and encrypts the PK using a customer code key. A customer's possession of his customer code allows him to decrypt the PK. Possession of the PK, in turn, allows the customer to decrypt the SK, which then allows him to decrypt "The Bells of St. Mary's."

A further understanding of the invention can be achieved by reading the following claim:

1. In a decrypting apparatus, usable by a subscriber to restricted-access television, and which decrypts digital television programs, the improvement comprising:

a) first computation means for decrypting program content which is encrypted by a relatively weak first key(SK)

b) second computation means, of substantially similar computational power as the first computation means, for decrypting a relatively stronger second key, which encrypts said first key (SK); and

c) means for receiving all externally supplied input including all program content and all keys, on a single input port, and delivering said input to the first and second computation means.

The prior art applied by the examiner in rejecting the claims follows:

Gammie et al. ("Gammie")

5, 237, 610

Aug. 17, 1993

Piosenka et al. ("Piosenka")

5, 389, 738

Feb. 14, 1995

Schneier Applied Cryptography, 265-78 and 357-63 (2d ed 1995). Claims 3 and 5 stand rejected under 35 U.S.C. § 112, ¶ 2, as indefinite. Claims 3 and 10 stand rejected under 35 U.S.C. § 112, ¶ 1, as non-enabled. Claim 10 stands rejected under § 112, ¶ 1, as lacking a written description. Claims 1, 5, 8, and 10 stand rejected under 35 U.S.C. § 102(b) as anticipated by Gammie. Claims 2 and 3 stand rejected under 35 U.S.C. § 103(a) as obvious over Gammie in view of Schneier. Claim 5 stands rejected under § 103(a) as obvious over Gammie in view of Piosenka.

OPINION

After considering the record, we are persuaded that the examiner did not err in rejecting claims 1 and 8 as anticipated, claim 2 as obvious, claim 3 as indefinite and non-enabled, and claim 10 as non-enabled and lacking a written description. He did err, however, in rejecting claim 3 as obvious; claim 5 as indefinite, anticipated, and obvious; and claim 10 as anticipated. Accordingly, we affirm-in-part. Our opinion addresses the following rejections:

• indefiniteness rejection of claims 3 and 5

• enablement rejection of claims 3 and 10

• written description rejection of claim 10

• anticipation and obviousness rejections of claims 1-3 8, and 10

• anticipation and obviousness rejections of claim 5.

I. Indefiniteness Rejection of claims 3 and 5

Rather than reiterate the arguments of the examiner or appellant in toto, we address the two points of contention therebetween. First, the examiner asserts, "[w]ith respect to claim 3, the meaning '[key] of triple-DES type' is unclear." (Examiner's Answer at 6.) The appellant argues that three sentences in "the specification, page 7," (Reply Br. at 12), clarify the meaning.

"The test for definiteness is whether one skilled in the art would understand the bounds of the claim when read in light of the specification. Orthokinetics Inc., v. Safety Travel Chairs, Inc., 806 F.2d 1565, 1576, 1 U.S.P.Q.2d 1081, 1088 (Fed. Cir. 1986). If the claims read in light of the specification reasonably apprise those skilled in the art of the scope of the invention, Section 112 demands no more. Hybritech, Inc. v. Monoclonal Antibodies, Inc., 802 F.2d 1367, 1385, 231 U.S.P.Q. 81, 94 (Fed. Cir. 1986)." Miles Labs., Inc. v. Shandon Inc., 997 F.2d 870, 875, 27 U.S.P.Q.2d 1123, 1126 (Fed. Cir. 1993).

Here, claim 3 specifies in pertinent part the following limitations: "said second key is of triple-DES type." One skilled in the art would understand DES to be a type of encryption algorithm, however, rather than a type of key. See Schneier, 270 ("DES is a block cipher. . . . DES is a symmetric algorithm.") The sentences relied on by the appellant confirm such a distinction by referring to "single-DES encryption," (Spec. at 7), and "more complex triple-DES encryption. . . ." (Id.) We agree with the examiner that "the phrase '[key] of triple-DES type' . . . is not defined." (Examiner's Answer at 12.) Although the sentences relied on by the appellant also disclose "using a 56-bit encryption key," (id.), and "a stronger 112-bit key," (id.), there is no mention of triple-DES type key. Therefore, we affirm the rejection of claim 3 as indefinite.

Second, the examiner asserts, "[w]ith respect to claims 5, the phrase 'said keys' recited in 5d lacks proper antecedent basis as it is unclear whether it refers to 'said first keys,' refers to 'said second keys,' or refers to 'both said first and second keys.'" (Examiner's Answer at 6.) The appellant argues that he "cannot see any reasonable interpretation of claim 5, wherein 'said keys' in paragraph (d) refers to anything other than all previously recited keys." (Reply Br. at 12.)

One skilled in the art would understand "said keys" to be a shorthand reference to all keys previously recited in claim 5, viz., to both the first and second keys. Therefore, we reverse the rejection of claim 5 as indefinite.

II. Enablement Rejection of Claims 3 and 10

We address the two points of contention between the examiner and appellant. First, the examiner asserts, "[t]he specification does not enable one of ordinary skill in the art to make and use the invention of claim 3. It is unknown how is one [sic] to make and use a triple DES type key." (Examiner's Answer at 7.) The appellant alleges, "[t]riple DES key" is a term-of-art. Such keys are well known." (Reply Br. at 6.)

"To be enabling under §112, a patent must contain a description that enables one skilled in the art to make and use the claimed invention." Atlas Powder Co. v. E. I. Du Pont de Nemours & Co., 750 F.2d 1569, 1576, 224 U.S.P.Q. 409, 413 (Fed. Cir. 1984)(citing Raytheon Co. v. Roper Corp., 724 F.2d 951, 960, 220 U.S.P.Q. 592, 599 (Fed. Cir. 1983)). "That some experimentation is necessary does not preclude enablement; the amount of experimentation, however, must not be unduly extensive." Id. at 1576, 224 U.S.P.Q. at 413. "Argument in the brief does not take the place of evidence in the record." In re Schulze, 346 F.2d 600, 602, 145 U.S.P.Q. 716, 718 (CCPA 1965)(citing In re Cole, 326 F.2d 769, 773, 140 U.S.P.Q. 230, 233 (CCPA 1964)).

Here, as explained regarding the indefiniteness of claim 3, one skilled in the art would understand DES to be a type of encryption algorithm rather than a type of key. No evidence in the record, moreover, supports the appellant's argument that such keys are well known. Absent a definition of the claimed "key . . . of triple-DES type," we are not persuaded that one skilled in the art would be able to make and use the claimed invention without undue experimentation. Therefore, we affirm the rejection of claim 3 as non-enabled.

Second, the examiner asserts, "[t]he specification does not enable one of ordinary skill in the art to make and use the invention of claim 10. The specification does not address what makes the bus (or any means) require that the 'key must be entered onto said bus in encrypted form to be accepted by a computation means.'" (Examiner's Answer at 8.) The appellant argues, "the only ports of entry for keys PK and SK are busses 55 and 56 in Figure 8 of the Specification. However, these keys must be entered in encrypted form onto these busses. If a non-encrypted key is entered, then gibberish will be delivered by the computation means." (Appeal Br. at 24-25.)

"Analysis begins with a key legal question -- what is the invention claimed?" Panduit Corp. v. Dennison Mfg. Co., 810 F.2d 1561, 1567, 1 U.S.P.Q.2d 1593, 1597 (Fed. Cir. 1987). Here, claim 10 recites in pertinent part the following limitations: "key (SK) must be entered onto said bus in encrypted form to be accepted by a computation means." Accordingly, the limitations require checking a key on a bus to determine whether the key is encrypted before the key can be accepted.

The next question is whether the claimed invention is enabled. Figure 8, cited by the appellant, "illustrates the decryption process occurring at the customer's site." (Spec. at 20.) In describing the decryption process, the appellant's specification merely mentions that "[k]ey SK is encrypted using PK as a key, as indicated by phrase [sic] 56, and is decrypted in block 23 using actual PK, on bus 63, to produce actual SK, on bus 64." (Spec. at 21.) The specification fails to mention, let alone describe,...