NOTE: This disposition is nonprecedential. 

## United States Court of Appeals for the Federal Circuit

2006-1603 DATA ENCRYPTION CORPORATION,Plaintiff/Counterclaim DefendantAppellant,

v. MICROSOFT CORPORATION, Defendant/Counterclaimant-Appellee, and DELL COMPUTER CORPORATION, Defendant-Appellee.

Roderick G. Dorman , Hennigan, Bennett & Dormann LLP, of Los Angeles, California, argued for plaint iff/counterclaimant defendant-appellant. With him on the brief were Lawrence M. Hadley , Bless S. Young , and Hazim H. Ansari

. Kelly C. Hunsaker , Fish & Richardson P.C., of Redwood City, California, argued for defendant/counterclaimant-appell ee. With him on the brief for Microsoft Corporation were Juanita R. Brooks and William Chad Shear , of San Diego, Calif ornia. Of counsel was Robert B. Lytle , Microsoft Corporation, of Redmond, Washington. Daniel T. Conrad , Jones Day, of Dallas Texas, argued for defendant-appellee. With him on the brief for De ll Computer Corporation was Mark N. Reiter . Of counsel was Amy E. Blackwelder

. Appealed from: United States District Cour t for the Central District of California Judge Manuel L. RealNOTE: This disposition is nonprecedential. 

## United States Court of Appeals for the Federal Circuit

2006-1603

DATA ENCRYPTION CORPORATION, Plaintiff/Counterclaim Defendant- Appellant,

v. MICROSOFT CORPORATION, Defendant/Counterclaimant- Appellee, and DELL COMPUTER CORPORATION, Defendant-Appellee.

__________________________ DECIDED: September 6, 2007

__________________________ Before RADER, BRYSON, and PROST, Circuit Judges

. PROST, Circuit Judge

. Plaintiff-Appellant, Data Encryption Co rporation (“Data”) appeal s the decision of the United States District Court for the Cent ral District of California granting summary judgment of noninfringement of U.S. Patent No. 5,584,023 (t he “’023 patent”) in favor of Defendants-Appellees, Microsoft Corpor ation (“Microsoft”) and Dell ComputerCorporation (“Dell”). Data Encryption Corp. v. Microsoft Computer Corp. , No. 05-CV05531 (C.D. Cal. Aug. 14, 2006). We affirm

. I. BACKGROUND Data is the owner of the ’023 patent, entitled “Computer System Including a Transparent and Secure File Transform Mechani sm.” Generally speaking, the ’023 patent is directed to computer systems that encrypt and decrypt files. On July 29, 2005, Data sued Microsoft and Dell, alleging that Microsoft’s Windows operating systems and Dell computers using Windows operating syst ems infringed claims 5-12 of the ’023 patent. The parties filed cross motions for su mmary judgment. On August 14, 2006, the district court (1) granted Mi crosoft’s motion for summary judgment of noninfringement, (2) granted Dell’s motion for summary j udgment of noninfringement, and (3) denied Data’s motion for partial summa ry judgment of infringement of claims 5, 6, and 7 by Microsoft and Dell. Data appeals. We have jurisdiction under 28 U.S.C. § 1295(a)(1). II. DISCUSSION
A On appeal, Data argues that the district court misconstrued the asserted claims and that, therefore, the distri ct court’s infringement analysis was incorrect. We review the district court’s clai m construction de novo. Cybor Corp. v. FAS Techs., Inc. , 138 F.3d 1448, 1456 (Fed. Cir. 1998) (en banc). We also review de novo the district court’s grant of summary judgment of noninfringement. O2 Micro Int’l Ltd. v. Monolithic Power Sys., Inc. , 467 F.3d 1355, 1369 (Fed. Cir. 2006).

2006-1603 2Of the asserted claims, claims 5 and 8 are independent. Claim 5 recites: 1 5. A computer system including a file encryption mechanism, said system comprising: a) a file store providing for t he storage of a file including one or more blocks of data; b) a memory store providing for t he storage of blocks of data in first and second logical data areas; and c) a processor coupled to said memo ry store and said file store for executing instructions impl ementing a com puter operating system as stored in said first logical data area and an application program as stored in said se cond logical data area, said processor providing for the controlled transfer of a predetermined block of data between said file store and said data store means, said processor including: i) an encryption routine, def ined by the execution of instructions of said co mputer operating system, for encrypting and decrypting said predetermined block of data in said first logical dat a area separately from another block of data; ii) a request routine, defined by the execution of instructions of said application progr am, for selecting said predetermined block of data to be operated on by the execution of instructions of said application program in said second logical data area; and iii) a system interface routine , defined by the execution of instructions of said co mputer operating system and responsive to said request routine, that controls the transfer of said predetermined block of data between said file store and said data st ore and between said first and second logical data areas of sa id data store, said system interface routine determining whether said predetermined block of data is encrypted as stored by said file store, said system interface routine select ively directing the transfer of said predetermined block of data between said first and second logical data areas through said encryption routine

. (Emphases added). The parties agreed before t he district court that the term “first logical data area” as recited in the claim refe rs to the kernel memo ry area and that the term “second logical data area” refers to the user memory area.

1 On appeal, Data presents no separat e argument regarding independent claim 8. We therefore discuss only independent claim 5.

2006-1603 3In granting summary judgment of noninfri ngement, the district court held that certain statements in the s pecification amounted to a disa vowal of coverage of systems that maintain data subject to encryption in an unencrypted state in the kernel memory buffer pool, or cache. Data Encryption Corp. v. Microsoft Computer Corp. , No. 05-CV05531, slip op. at 2 (C.D. Cal. Aug. 14, 2006) (order granting Microsoft’s motion for summary judgment). The court further held that the phrase “system interface routine selectively directing the transfer of said predetermined block of data between said first and second logical data areas through said enc ryption routine” requires that “the encryption routine in kernel memory transforms (i.e., encrypts or decrypts) the data in user memory when it is transferred betw een kernel memory and user memory, not when it is transferred between memory and the disk.” Id. In light of its interpretation, the court concluded that ther e was no genuine dispute as to any material fact that Microsoft Windows products did not infr inge any of the asserted claims and, accordingly, granted summary judgment to Microsoft and Dell. Id. , slip op. at 2-3; Data Encryption Corp. v. Microsoft Computer Corp. , No. 05-CV-05531, slip op. at 2 (C.D. Cal. Aug. 14, 2006) (order granting Dell’s motion for summary judgment).
B At issue is the proper construction of the phrase “system interface routine selectively directing the transfer of said predetermined block of data between said first and second logical data areas through said encry ption routine.” Da ta argues that the district court incorrectly concluded that the inventor disavowed coverage of systems that maintain data subject to encryption in an unenc rypted state in the kernel memory buffer pool.

2006-1603 4We agree with the district cour t that the specification reveals a disavowal of claim
scope. See Phillips v. AWH Corp. , 415 F.3d 1303, 1316 (Fed. Cir. 2005) (en banc) ([T]he specification may reveal an intentional disclaimer, or disavowal, of claim scope by the inventor. In that instance . . ., the in ventor has dictated the correct claim scope, and the inventor’s intention, as ex pressed in the specification, is regarded as dispositive.”). The ’023 patent specification explains t hat, in accordance with the invention, data pending either a read or write operation to disk 22 or other storage medium persists only in an encrypted state. All data subject to encryption by operation of the present invention is maintained in an encrypted state in the buffer pool. 2 ’023 patent, col. 14, ll. 10- 14 (emphasis added). This language is unambiguous. By stating that “[a]ll dat a subject to encryption by operati on of the present invention is maintained in an encrypted state in the [ker nel memory] buffer pool,” the inventor has disavowed coverage of systems that mainta in data subject to encryption in an unencrypted state in the kernel memory buffer pool. Data nevertheless asserts that the above-quoted language should not inform the construction of claim 5—and should therefor e not amount to a disavowal of claim scope—because claim 5 makes no mention of how data is “maintained” in the kernel memory buffer pool. While it is true that claim 5 makes no mention of how data is maintained in the kernel memory buffer pool, it is also true that clai m 5 specifies that the system decrypts data when it is transferred from the kernel memory to the user memory. Specifically, claim 5 requires the syst em to “selectively direct[] the transfer of said predetermined block of data between said first and second logical data areas[, i.e.,

2 The buffer pool is located withi n the kernel memory area. See ’023 patent, col. 5, ll. 63-64 (“Withi n the kernel space, a buffer pool, or buffer cache, is maintained by the operating system.”).

2006-1603 52006-1603 6 between the kernel memory and the user memo ry,] through said encryption routine.” Thus, the specification’s stat ement that “[a]ll data subject to encryption by operation of the present invention is maintained in an enc rypted state in the [kernel memory] buffer pool” is clearly relevant to claim 5’s requi rement that data be dec rypted upon its transfer from the kernel memory to the user memory. In light of the inventor’s disavowal of claim scope, we affirm the district court’s grant of summary judgment of noninfringement. Data does not dispute that, in normal operation, Windows operating systems maintain data subject to encryption in an unencrypted state in the kernel memory buffer pool, or cache. Notwithstanding the disavowal, Data ar gues that there is a genuine issue of material fact regarding infringement by operation of Windows oper ating systems in nondefault mode. We have carefully examined Data’s arguments in this regard and find them to be unpersuasive. We similarly fi nd unpersuasive Data’s contention that the district court erroneously denied its motion fo r further discovery pursuant to Federal Rule of Civil Procedure 56(f). III. CONCLUSION For the above reasons, we affirm the distri ct court’s judgment of noninfringement.