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Luciano F. Paone v. Microsoft Corporation

July 30, 2012

LUCIANO F. PAONE,
PLAINTIFF,
v.
MICROSOFT CORPORATION,
DEFENDANT.



The opinion of the court was delivered by: Spatt, District Judge.

MEMORANDUM OF DECISION AND ORDER

In this patent infringement case, the Plaintiff Luciano F. Paone ("Paone") alleges that the Defendant Microsoft Corporation ("Microsoft") has infringed United States Patent 6,259,789 ("the '789 Patent"), which Paone holds. Pursuant to the Supreme Court's decision in Markman v. Westview Instruments, Inc., 517 U.S. 370, 116 S. Ct. 1384, 134 L. Ed. 2d 577 (1996), the Court previously construed the disputed claim terms of the '789 Patent. Presently before the Court is the Defendant's motion for summary judgment. For the reasons set forth below, the motion is granted in part and denied in part.

I. BACKGROUND

A. Background of the Invention

For purposes of the present motion, the Court will restate the relevant facts as they appeared in the previous claim construction decision issued on February 9, 2011 (the "Markman Order"). See generally Paone v. Microsoft Corp., 771 F. Supp. 2d 224 (E.D.N.Y. 2011).

On July 10, 2001, the United States Patent and Trademark Office ("PTO") issued the '789 Patent, entitled "Computer Implemented Secret Object Key Block Cipher Encryption and Digital Signature Device and Method", to the Plaintiff Luciano F. Paone. The '789 Patent describes a method of translating (or "encrypting") ordinary data (called "plaintext") into encoded data (called "ciphertext"), so that the plaintext may not be viewed by an unintended reader. In cryptography, which is the science of encryption, such a method is called a "cipher". Generally, encrypted ciphertext is later decoded, or "decrypted", into plaintext, so that the data is again usable.

There are several ways to encrypt computer data, but the '789 Patent deals exclusively with "symmetric key" encryption of computer data, which requires that the encryptor and decryptor share knowledge of both a cipher and a key. Computer based symmetric key ciphers divide roughly into two types: block ciphers and stream ciphers. As a general matter, a stream cipher employs its key to encrypt data one bit at a time, while a block cipher employs its key to encrypt bits in groups. The '789 Patent describes a block cipher.

Computer implemented block ciphers have been in wide use in the United States since at least 1976, when a block cipher called the "Data Encryption Standard" or "DES" was adopted by the United States government for general use. As of 1997, when Paone filed his patent application, dozens of additional block encryption algorithms had been published. However, most of those inventions used a single key to encrypt successive blocks of data. Paone's innovation-in the most general terms-was to change the encryption key for each data block, based on additional, randomly generated data.

B. Infringing Technology

There are two components of Microsoft's flagship computer operating system, Windows, that Paone asserts infringe the '789 Patent. Temporal Key Integrity Protocol ("TKIP") encryption is an industry-standard data encryption protocol used to encrypt and decrypt data that is transmitted over wireless local area networks. TKIP technology improves on prior wireless encryption standards by using a dynamic keying scheme in which the encryption key changes from one block of data to the next. The Defendant Microsoft implements or supports TKIP in many of its products, including Windows Vista, XP and 7, and Xbox 360. Paone claims that method claims 2 and 33 in the '789 Patent, as well as system claims 24 and 34 in the '789 Patent, are infringed by the TKIP technology. In order for TKIP to infringe any these claims, Paone necessarily must prove that TKIP incorporates every limitation of the claim, either literally or under the doctrine of equivalents.

The second component Paone asserts as being infringed is BitLocker. BitLocker is an encryption feature implemented in Microsoft software, which is used to encrypt and decrypt data on a customer's hard drive. BitLocker targets the "lost laptop" scenario, in which unprotected data could be vulnerable to theft or offline attacks. The BitLocker technology encrypts data on a hard drive using an encryption key that changes from one block of data to the next. As with TKIP, Microsoft has incorporated the BitLocker feature into a number of its products, including Windows Vista and 7 Ultimate. Paone claims that the method claims 2 and 33 in the '789 Patent are infringed by the BitLocker technology. In order for BitLocker to infringe either of these claims, Paone necessarily must prove that BitLocker incorporates every limitation of either of the claims, either literally or under the doctrine of equivalents.

In sum, Paone alleges that Microsoft's products implementing and supporting TKIP encryption infringe claims 2, 24, 33 and 34 of the '789 Patent, while products incorporating Microsoft's BitLocker encryption feature infringe claims 2 and 33 of the '789 Patent.

C. Procedural History

Paone filed his application for the '789 Patent on December 12, 1997. Following the initial application, the PTO rejected Paone's claims as unpatentable in three successive office actions, dated September 29, 1999, March 16, 2000, and October 30, 2000. In response to each of these rejections, Paone modified his claims and provided additional argument. Then, on July 10, 2001, the PTO deemed the described invention patentable, and issued the '789 Patent.

On July 23, 2007, Paone commenced the present action against Microsoft, alleging that Microsoft was infringing the '789 patent. Specifically, Paone asserts that two components of Microsoft's flagship computer operating system, Windows, infringe the '789 Patent, as set forth above. The parties proceeded with discovery, during which time Microsoft on May 16, 2008 requested the PTO to re-examine the '789 Patent. In early 2009, with the reexamination proceeding still pending, the parties briefed claim construction motions. However, before holding a Markman hearing, the Court on April 5, 2009 stayed the case pending the resolution of the reexamination proceeding. Then, before the stay was lifted, Microsoft also filed two more reexamination requests, dated June 29, 2009, and July 27, 2009. The three reexamination proceedings as a whole resulted in the cancellation of claims 1, 3, 23, and 32 of the '789 Patent, but also a ruling that several claims, including claims 2, 24, 33, and 34, were patentable. After certain amendments, a number of other claims were also found to be patentable.

After the reexamination proceedings had been finalized, the Court on March 3, 2010 lifted the stay of the case. Partly as a result of the reexamination proceedings, Paone modified his position to assert that Microsoft was infringing claims 2, 24, 33, and 34 of the '789 Patent, all of which had been ruled patentable by the PTO. These claims read in full as follows (the language of claims 1, 23, and 32 are also included, because some of the asserted claims are dependent on those claims).

What is claimed is:

1. A computer implemented method for encrypting data comprising the steps of: creating at least one object key in a block cipher, the at least one object key comprising data and methods that operate on said data; creating a key schedule based upon the at least one object key; encrypting a random session object key in a block cipher encryption process with the at least one object key; encrypting a block of input plaintext data utilizing said key schedule; modifying the at least one object key based on seeding from the random session object key; modifying the key schedule based upon the at least one modified object key; encrypting a next block of input plaintext data utilizing said modified key schedule; and repeating the steps of modifying the at least one object key, modifying the key schedule and encrypting utilizing the modified key schedule until the encrypting of blocks of plaintext data is completed.

2. A computer implemented method as defined in claim 1, wherein the modification of the key schedule is independent of the input plaintext data.

23. A cryptographic communications system comprising: at least two networked computer systems linked by a communication channel; and each computer system including a central processing unit and a memory storage device for executing a block cipher encryption/decryption process; wherein the encryption process transforms an input plaintext message to a ciphertext message and the decryption process transforms the ciphertext message to the input plaintext message, the encryption/decryption process using at least one dynamic object key which is modified using a non-linear function for each block of input data, each object key being associated with a different key schedule to encrypt/decrypt the input plaintext/output ciphertext message.

24. A cryptographic communications system as defined in claim 23, wherein the encryption/decryption process further includes the use of a random session object key having an initial state randomly generated by the computer system, and wherein the object key modifications are based on seeding from the random session object key.

32. A computer implemented method for encrypting data comprising the steps of: creating at least one object key in a block cipher, the at least one object key comprising data and methods that operate on said data; creating a key schedule based upon the at least one object key; encrypting a block of input plaintext data utilizing said key schedule; modifying the at least one object key based on at least a non-linear function; modifying the key schedule based upon the at least one modified object key; encrypting a next block of input plaintext data utilizing said modified key schedule; and repeating the steps of modifying the at least one object key, modifying the key schedule and encrypting utilizing the modified key schedule until the encrypting of blocks of plaintext data is completed.

33. A computer implemented method as defined in claim 32, where in the nonlinear function is a hashing function.

34. A cryptographic communications systems [sic] as defined in claim 23, wherein the non-linear function is a hashing function.

It is crucial to note that claims 2 and 33 in the '789 Patent are method claims. See In re Kollar, 286 F.3d 1326, 1332 (Fed. Cir. 2002) ("the distinction between a claim to a product, device, or apparatus, all of which are tangible items, and a claim to a process, which consists of a series of acts or steps."); see also NTP, Inc. v. Research In Motion, Ltd., 418 F.3d 1282, 1322 (Fed. Cir. 2005) ("The invention recited in a method claim is the performance of the recited steps."). "The law of this circuit is axiomatic that a method claim is directly infringed only if each step of the claimed method is performed." Muniauction, Inc. v. Thomson Corp., 532 F.3d 1318, 1328 (Fed. Cir. 2008). Paone claims that both of the methods claims are infringed by TKIP and BitLocker. On the other hand, 24 and 34 are systems claims, and not method claims. Paone claims that both of these claims are infringed, but only by TKIP and not by BitLocker.

Upon the lifting of the stay, the parties resumed their claim construction motions. Then, on the consent of the parties, the Court appointed Gale R. Peterson, Esq., an experienced and well-regarded patent attorney, as a special master in this case for the limited purpose of conducting a Markman hearing and issuing a report and recommendation to the Court on claim construction. On June 23, 2010 Special Master Peterson conducted a non-evidentiary Markman hearing, at which the parties' attorneys presented their arguments on claim construction. On August 11, 2010, Special Master Peterson issued an extensive and detailed Report and Recommendation on claim construction (the "Special Master's Report"). In response to this report, both Paone and Microsoft filed memoranda of law on September 17, 2010, each objecting in part to the Special Master's Report.

Prior to the Markman hearing, the parties presented nine claim terms for construction. However, after meeting and conferring at the suggestion of the Special Master, the parties agreed on meanings for three of those terms. The remaining six terms that were in dispute were:

Asserted Claims (or underlying independent claims) Containing the Disputed Terms/Phrases Disputed Terms/Phrases "object key" 1, 23, 24, 32 "random session object key" 1, 24 "repeating the step[] of modifying the at least one object key" 1, 32 "block" 1, 23, 32 "key schedule" 1, 2, 23, 32 "block cipher" 1, 23, 26, 32

On February 9, 2011, this Court issued a decision construing these six claim terms (the "Markman Order"). As for "object key", the Court concluded that the "object key" is an encryption key that is not available to the general public, and which is composed of both (1) key data and (2) methods that modify that key data. The Court also found that the object key need not be implemented in an object-oriented programming language. As for "random session object key", the Court construed the term to mean an object key, as defined above, with data that is generated randomly for each instance of the use of the encryption application. As for "repeating the step[] of modifying the at least one object key", the Court found the phrase to be understood as limited in the sense that the object key's data, as it presently exists in the object key at each instance of modification, must be an input into the modification methods of that object key. As for "block", the Court adopted in its entirety the Special Master's analysis and construction of the term, which is:

The term "block" as used in the claims and specification of the '789 patent means a sequence of bits wherein that sequence has a fixed length that does not vary from block-to-block. The length of a block may be determined through selection in an encryption algorithm. Plaintext data having a length longer than the length of a block is divided into blocks of fixed length.

As for "key schedule", the Court construed this term as a string of bits that is used in encrypting a block of input plaintext data. Moreover, the Court explained that it is created by using an object key as an input to an expansion function, which increases the size of the object key to form the key schedule. In addition, sub-portions of the key schedule must be accessible to be used separately in the encryption algorithm if called for, but those sub-portions may be accessed merely by identifying those sub-portions' positions in the string of bits that forms the key schedule. Finally, as for "block cipher", the Court found that a cipher that encrypts data in blocks, but does so by performing a single, successive, comparison of each element of the data block to an element of key data, is not a block cipher as the term is used in the '789 Patent.

On December 21, 2011, the Defendant Microsoft filed the instant motion for summary judgment requesting a determination of non-infringement.

II. DISCUSSION

A.Legal Standard on a Motion for Summary Judgment

Summary judgment is appropriate "if the pleadings, the discovery and disclosure materials on file, and any affidavits show that there is no genuine issue as to any material fact and that the movant is entitled to judgment as a matter of law." Fed. R. Civ. P. 56(c). A genuine issue of material fact exists if "the evidence is such that a reasonable jury could return a verdict for the nonmoving party." Anderson v. Liberty Lobby, Inc., 477 U.S. 242, 248, 106 S. Ct. 2505, 91 L. Ed. 2d 202 (1986). "Where the record taken as a whole could not lead a rational trier of fact to find for the non-moving party, there is no genuine issue for trial." Matsushita Elec. Indus. Co., Ltd. v. Zenith Radio Corp., 475 U.S. 574, 587, 106 S. Ct. 1348, 89 L. Ed. 2d 538 (1986) (citation and internal quotation marks omitted).

"The standard for summary judgment in a patent case is the same as in any other case." CA, Inc. v. Simple.com, Inc., No. 02 Civ. 7248, 2009 WL 7445199, at *2 (E.D.N.Y. Mar. 5, 2009) (citing Desper Prods., Inc. v. QSound Labs, Inc., 157 F.3d 1325, 1332 (Fed. Cir. 1998) and Union Carbide Corp. v. Am. Can Co., 724 F.2d 1567, 1571 (Fed. Cir. 1984)). Summary judgment on the ground of noninfringement of a patent, the relevant inquiry in this case, may be granted "where the patentee's proof is deficient in meeting an essential part of the legal standard for infringement liability." Johnston v. IVAC Corp., 885 F.2d 1574, 1577 (Fed. Cir. 1989); see Travel Sentry, Inc. v. Tropp, 736 F. Supp. 2d 623, 631 (E.D.N.Y. 2010).

"When deciding issues in a patent case, a district court applies the law of the circuit in which it sits to nonpatent issues and the law of the Federal Circuit to issues of substantive patent law." In re Omeprazole Patent Litig., 490 F. Supp. 2d 381, 399 (S.D.N.Y. 2007) (citing Invitrogen Corp. v. Biocrest Mfg., L.P., 424 F.3d 1374, 1378--79 (Fed. Cir. 2005)); see, e.g., Desenberg v. Google, Inc., No. 09 Civ. 10121, 2009 WL 2337122, at *5 (S.D.N.Y. July 30, 2009).

In this case, there is no dispute that the '789 Patent has been deemed valid upon its initial examination and subsequent reexamimnation. Accordingly, the only issues remaining for determination with respect to the patent are infringement and damages. At this stage of the litigation, the Defendant contends that it is entitled to summary judgment on the remaining issue of patent infringement.

B.Patent Infringement

Pursuant to 35 U.S.C. § 271(a), "whoever without authority makes, uses, offers to sell, or sells any patented invention, within the United States or imports into the United States any patented invention during the term of the patent therefor, infringes the patent." Patent infringement is "a strict liability offense". In re Seagate Technology, LLC, 497 F.3d 1360, 1368 (Fed. Cir. 2007), cert. denied sub nom. Convolve, Inc. v. Seagate Technology, LLC, 552 U.S. 1230, 128 S. Ct. 1445, 170 L. Ed. 2d 275 (2008). Thus, while intent is not necessarily an element of a direct infringement claim, an alleged infringer cannot claim ignorance or a good faith belief of non-infringement in order to defend against a claim of infringement. See In re Omeprazole Patent Litig., 490 F. Supp. 2d 381, 413 (S.D.N.Y. 2007) ("Making, using, selling, or offering to sell matter covered by a patent without authority of the owner constitutes infringement regardless of knowledge or intent."), aff'd, 281 Fed. App'x. 974 (Fed. Cir. 2008), cert. denied sub nom. Apotex Corp. v. Astrazeneca AB, ---U.S. ----, 129 S. Ct. 1593, 173 L. Ed. 2d 677 (2009); see also Metal Film Co. v. Metlon Corp., 316 F. Supp. 96, 111 n.15 (S.D.N.Y. 1970) ("neither lack of knowledge of the patent nor lack of intent to infringe is a defense on the issue of infringement.").

To assess a patent infringement claim, there are two relevant inquiries. "First, the court must construe the patent's claims as a matter of law to determine their proper scope." Serby v. First Alert, Inc., No. 09 Civ. 4229, 2011 WL 4464494, at *4 (E.D.N.Y. Sept. 26, 2011). This task was previously completed by the Court in the Markman Order. "Second, a jury generally determines the factual issue of whether infringement has occurred, unless there is no genuine issue of material fact, in which case summary judgment is appropriate." Id. Thus, as the Court previously resolved all disputes over the language of the patent claims, the issue of infringement may be resolved as a matter of law on a motion for summary judgment. See Moore U.S.A. Inc. v. The Standard Register Co., 144 F. Supp. 2d 188, 191--92 (W.D.N.Y. 2001); see also Gart v. Logitech, Inc., 254 F.3d 1334, 1339 (Fed. Cir. 2001) (noting that infringement is properly decided upon summary judgment when no reasonable jury could find that every limitation recited in the properly construed claim either is or is not found in the accused device), cert. denied, 534 U.S. 1114, 122 S. Ct. 921, 151 L. Ed. 2d 886 (2002); Wolverine World Wide, Inc. v. Nike, Inc., 38 F.3d 1192, 1199 (Fed. Cir. 1994) ("In order for a court to find infringement, the plaintiff must show the presence of every . . . [limitation] or its substantial equivalent in the accused device.").

Paone asserts that there is infringement by Microsoft as to four claims of the '789 patent. In particular, the Plaintiff asserts that four claims----2, 24, 33, and 34----are infringed in connection with the TKIP component, and two claims----2 and 33----are infringed in connection with the BitLocker component. As for the latter, all of the infringement claims in connection with BitLocker are asserted under the doctrine of equivalents ("DOE"), namely, not literal infringement. The Plaintiff's claims are summarized as follows:

Claim Accused Technology Infringement Theory 2 (method) TKIP BitLocker DOE 33 (method) TKIP BitLocker DOE 24 (system) TKIP Literal DOE 34 (system) TKIP Literal DOE

The core of the Defendant's present summary judgment motion on the basis of non-infringement is that neither of Microsoft's accused technologies-TKIP nor BitLocker-fall within the claim boundaries of the '789 patent set by the Court's previous Markman Order. "[I]nfringement is assessed by comparing the accused device to the claims[;] the accused device infringes if it incorporates every limitation of a claim, either literally or under the doctrine of equivalents." Nazomi Commc'ns, Inc. v. Arm Holdings, PLC, 403 F.3d 1364, 1732 (Fed. Cir. 2005) (emphasis added). If, however, even one claim limitation is missing or not met, there is no literal infringement. Mas-Hamilton Group v. LaGard, Inc., 156 F.3d 1206, 1211 (Fed.Cir.1998). The Defendant's arguments center on three claim limitations; two of the limitations are found in all four claims, one of the limitations is found in only two claims.

The first limitation at issue is "block", which is contained in all four claims. Microsoft contends that TKIP cannot meet this claim limitation either literally or under the doctrine of equivalents, and therefore TKIP cannot be found to infringe any of the four claims. See z4 Techs., Inc. v. Microsoft Corp., 507 F.3d 1340, 1348 (Fed. Cir. 2007) ("We presume, unless otherwise compelled, that the same claim term in the same patent or related patents carries the same construed meaning." (internal quotation marks omitted)). As a practical matter, if Microsoft ultimately prevails on this argument, then claims 2, 33, 24, and 34 cannot be infringed by TKIP.

The next limitation at issue is the "object key" limitation, which also is contained in all four claims. Microsoft maintains that neither TKIP nor BitLocker meet this claim limitation, and therefore neither component can be found to infringe any of the four claims. Again, as a practical matter, if Microsoft ultimately prevails on this argument, then claims 2, 33, 24, and 34 cannot be infringed by TKIP or BitLocker.

The last limitation at issue is the "repeating step" limitation, which is only contained by incorporation in the method claims 2 and 33. Microsoft maintains that neither TKIP nor BitLocker meet this claim limitation, and therefore neither component can be found to infringe the two method claims. As a practical matter, if Microsoft ultimately prevails on this argument, then claims 2 and 33 cannot be infringed by TKIP or BitLocker.

Ultimately, the resolution of one of these contentions has the potential to dispose of the entire matter, or at least dispose of certain claims that are at issue. For instance, if there is no question of fact that BitLocker does not meet the "repeating step" limitation found in the method claims 2 and 33, then it is irrelevant whether it also meets the "object key" limitation in those two claims. However, for purposes of the present motion, the Court will fully address all issues raised by the parties and will assess each claim limitation independently. In the conclusion, the Court will summarize the practical effect of the Court's findings on the claims that remain.

C.As to Whether Microsoft Encrypts "Blocks" of Plaintext with a "Block Cipher"

The first relevant inquiry is whether Microsoft's TKIP component literally infringes the '789 patent or infringes under the doctrine of equivalents, in light of the method in which TKIP encrypts "blocks" of plaintext with a "block cipher".

As mentioned above, TKIP is an industry-standard data encryption protocol used to encrypt and decrypt data that is transmitted over wireless local area networks. The Defendant Microsoft implements or supports TKIP in many of its products. The data units used in the TKIP encryption, called MAC Protocol Data Units ("MPDUs"), are the only components that could potentially qualify as "blocks" in a "block cipher" under the '789 patent.

When a data message such as a computer document is transmitted over a TKIP-enabled network, the system determines the size of the message and compares it to the maximum TKIP block size, also known as the "fragmentation threshold." If, and only if, the message has a length that is precisely an exact multiple of the applicable fragmentation threshold, will this result in an encryption where each and every MPDU has the same length. However, if the message length exceeds the fragmentation threshold, the message will be fragmented and encrypted (and subsequently decrypted) as a series of TKIP MPDUs, with the final MPDU having a different length. This last MPDU consists of what are the leftover bits after the message is divided. The capability to split a data message if the fragmentation threshold is exceeded is a requirement of the TKIP standard.

According to Microsoft, every asserted claim-2, 33, 24, and 34-requires encryption of "blocks" of plaintext in a "block cipher." (See '789 patent claims 2, 33, 24 & 34.) Thus, in order to prove infringement, Paone would necessarily need to demonstrate at trial that Microsoft's TKIP component satisfies these limitations in the claims. Honeywell Int'l, Inc. v. United States, 70 Fed. Cl. 424, 446 (Fed. Cl. 2006) (noting that a prima facie case of literal infringement requires the accused matter to fall clearly within the patent claim, meaning that "every limitation of a claim [must] be met to establish literal infringement.") (quoting Intellicall, Inc. v. Phonometrics, Inc., 952 F.3d 1384, 1389 (Fed. Cir. 1992) (overturned on other grounds); see also Research Plastics, Inc. v. Federal Packaging Corp., 421 F.3d 1290, 1297 (Fed. Cir. 2005) ("Literal infringement requires that the accused device embody each of the limitations of the asserted claim."). In other words, for Microsoft to succeed on its motion for summary judgment, it must show that there is no genuine issue of material fact as to whether TKIP encrypts plaintext "blocks" and does so in a "block cipher". Microsoft contends that the record clearly confirms that TKIP contains neither of these elements either literally or equivalently, and accordingly, cannot be found to infringe the '789 patent.

1."Block"

As previously and thoroughly analyzed in the Markman Order, the claim term "block" is used to describe groups of data to be encrypted or decrypted. As relevant to the allegedly infringed claims, the term appears in claim 1 (incorporated by reference in claim 2), claim 23 (incorporated by reference in claims 24 and 34), and claim 32 (incorporated by reference in claim 33). For example, claim 1 describes the methods of the invention as including the steps of: encrypting a block of input plaintext data utilizing said key schedule; . . . encrypting a next block of input plaintext data utilizing said modified key schedule; and repeating the step[] of . . . encrypting utilizing the modified key schedule until the encrypting of blocks of plaintext data is completed. ('789 Patent, 11:26--38 (emphasis added).) The systems claims-24 and 34-state that a dynamic object key is modified "for each block of input data." (Id. at 11:28--30 (emphasis added).)

The primary dispute between the parties at the time of claim construction regarding the claim term "block" was whether it required that all blocks of data in a given encryption be of the same length, or whether the block length could vary among blocks. Paone's patent contained a preferred embodiment where the blocks have a "fixed length"; namely, each block contains 512 bits of information. The patent application explains that data blocks of 512 bits (64 bytes) each are encrypted, and that the input file will be padded with random bytes in order to produce a file with a length having a multiple of 512 bits. Nevertheless, Paone proposed at the claim construction stage that blocks are simply groups of data that are input into the block cipher. The Plaintiff further suggested that each block must have a fixed length, so that the length is "known to the cipher algorithm", but that there is no limitation in the patent that each and every block must be set to the same size. On the other hand, Microsoft contended that "block" meant a string of fixed length that applies to all strings of data, as defined by a block cipher.

Ultimately, the Court concurred with the Special Master and found that the term "block" as used in the claims and specification of the '789 patent means "a sequence of bits wherein that sequence has a fixed length that does not vary from block-to-block. The length of a block may be determined through selection in an encryption algorithm. Plaintext data having a length longer than the length of a block is divided into blocks of fixed length." (Markman Order, at 43.) The Court explicitly accepted the Defendant's interpretation that every block must be the same size and thus be "not subject to change or variation", thereby rejecting Paone's interpretation that "fixed" meant only "determined, established, or set". (Special Masters Report, at 197.)

Therefore, in order for Microsoft to literally infringe the relevant four claims of the '789 patent, the blocks in TKIP's encryption would necessarily need to have a fixed length, and that length cannot vary from block-to-block. The Defendant asserts that it is entitled to summary judgment on the ground that the blocks in TKIP do not necessarily have the same length from block-to-block, and consequently cannot literally infringe. In addition, the Defendant contends that it cannot be found to have infringed under the doctrine of equivalents, as posited by the Plaintiff. The Court will address each of these contentions in turn.

a.Literal Infringement

Literal infringement of a claim occurs when every limitation recited in the claim appears in the accused device, i.e., when "the properly construed claim reads on the accused device exactly." Amhil Enters., Ltd. v. Wawa, Inc., 81 F.3d 1554, 1562 (Fed. Cir. 1996).

As an initial matter, the Court notes that based upon the evidence in the record, there is no question of fact that TKIP allows in theory for two different scenarios: one in which MPDU blocks are all the same length, and one in which the MPDU blocks are not all the same length. The Plaintiff does not appear to dispute this fact in its opposition papers or in its Local 56.1 Statement. (See Pl. Resp. 56.1, ...


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