DivX, LLC

Patent Trials and Appeals Board

Dec 16, 2020

IPR2020-00614 (P.T.A.B. Dec. 16, 2020)

Trials@uspto.gov Paper 13
571-272-7822 Date: December 16, 2020

UNITED STATES PATENT AND TRADEMARK OFFICE
_____________

BEFORE THE PATENT TRIAL AND APPEAL BOARD
____________

NETFLIX, INC. and HULU, LLC,
Petitioner,

v.

DIVX, LLC,
Patent Owner.
____________

IPR2020-00614
Patent 7,295,673 B2
____________

Before BART A. GERSTENBLITH, MONICA S. ULLAGADDI, and
IFTIKHAR AHMED, Administrative Patent Judges.

ULLAGADDI, Administrative Patent Judge.

DECISION
Granting Petitioner’s Request on Rehearing
37 C.F.R. § 42.71(d)
Granting Institution of Inter Partes Review
35 U.S.C. § 314

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I. INTRODUCTION
A. Background
Netflix, Inc. and Hulu, LLC (“Petitioner”) filed a Petition to institute
an inter partes review of claims 1–6, 9, 10, and 13–19 (“the challenged
claims”) of U.S. Patent No. 7,295,673 B2 (Ex. 1001, “the ’673 patent”).
Paper 3 (“Pet.”). DivX, LLC (“Patent Owner”) filed a Preliminary
Response. Paper 7 (“Prelim. Resp.”). With our authorization, Petitioner
thereafter filed a Reply (Paper 9 (“Prelim. Reply”)) and Patent Owner filed a
Sur-reply (Paper 10 (“Prelim. Sur-reply”)).
In our Decision Denying Institution of Inter Partes Review, we
concluded that Petitioner failed to establish a reasonable likelihood of
prevailing in demonstrating that any of the challenged claims are
unpatentable. Paper 11 (“Decision” or “Dec.”). Specifically, we concluded
that Petitioner’s challenge did not sufficiently demonstrate that the claimed
“frame encryption function” encompasses conventional encryption
algorithms. See, e.g., id. at 10–11. Accordingly, we declined to institute
trial on the challenged claims of the ’673 patent. Id. at 21.
Petitioner filed a request for rehearing (Paper 12, “Rehearing Request”
or “Reh’g Req.”) of our Decision. For the reasons set forth below, the
request is granted.
II. STANDARD OF REVIEW
The burdens and requirements of a request for rehearing are stated in 37
C.F.R. § 42.71(d):
(d) Rehearing. . . . The burden of showing a decision should be
modified lies with the party challenging the decision. The
request must specifically identify all matters the party believes
the Board misapprehended or overlooked, and the place where
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each matter was previously addressed in a motion, an opposition,
or a reply.
III. PETITIONER’S REHEARING ARGUMENTS
With respect to teaching the claimed “frame encryption function”
recited in independent claim 1, Petitioner contends that “the Petition did not
rely on conventional encryption algorithms alone . . . .” Reh’g Req. 6 (citing
Pet. 33–35; Ex. 1005, 5:28–60, 6:24–40; Ex. 1003 ¶¶ 154–156). Instead,
according to Petitioner,
[T]he Petition pointed to the use of encryption algorithms
together with Demos’ selection of frames and Fetkovich’s
encryption parameters, which specify the location of encrypted
portions of a frame, including the layout (e.g., every fourth slice)
and offset (e.g., the number of slices at the beginning of the frame
before the first encrypted slice), and the application of those
encryption parameters to selected frames, including by frame
type for I and P frames.
Id. (emphases added); id. at 2–5.1 Petitioner asserts that “the Decision
overlooked the Petition’s explanation that the prior art teaches using
encryption algorithms together with encryption parameters” and that “[t]he
Decision did not analyze the encryption parameters or selective encryption
taught by Fetkovich or Demos.” Id. at 9 (citing Reh’g Req. § III.A;
Dec. 18–19).2 Petitioner further asserts that “the Petition did not rely on
DES [Data Encryption Standard] alone—it explained that the prior art taught
‘encryption algorithms and encryption parameters together control the
encryption process, including the portions of the video stream to encrypt.’”
Id. at 7 (citing Pet. 35; Reh’g Req. § III.A) (emphasis omitted).

1 U.S. Patent 7,151,832 B1, issued Dec. 19, 2006 (Ex. 1005, “Fetkovich”).
2 U.S. Patent 6,957,350 B1, issued Oct. 18, 2005 (Ex. 1006, “Demos”).
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We are persuaded that we misapprehended Petitioner’s position––that
it is Fetkovich’s and Demos’ selection of encryption-related parameters and
portions in combination with their respective disclosures of conventional
encryption algorithms that teach or suggest the claimed “frame encryption
function.” We did not appreciate, in our Decision, that Petitioner’s position
regarding the claimed “frame encryption function” is based on two steps––
the step of selecting what to encrypt, followed by the step of encrypting by
providing the selections as input to a conventional encryption algorithm.
More particularly, we now understand Petitioner’s position to be based on
selecting which frames to encrypt as taught by Demos combined with
selecting which portions of the frames to encrypt as taught by Fetkovich, and
providing those selections to a conventional encryption algorithm as taught
by each of Ueno, Demos, and Fetkovich to encrypt the selected frames and
portions.3,4 See Pet. 33. We are persuaded that the Petition supports this
position, on the current record. Id. at 33–35. From our review of the
disclosures cited by Petitioner, we determine Petitioner’s challenge
sufficiently demonstrates a two-step process of selecting followed by
encrypting, which we determine is encompassed by our construction of
frame encryption function, based on the current record. Infra § IV.B.1.

3 In an alternative position, Petitioner relies on Demos to teach both
selecting which frames to encrypt (e.g., I-frames, or I- and P-frames) and
selecting which portions (i.e., AC or DC coefficients) to encrypt, which we
address below. Pet. 35 (citing-in-part Ex. 1006, 23:17–24:18); see infra
§ IV.C.4.
4 U.S. Patent 5,574,785, issued Nov. 12, 1996 (Ex. 1004, “Ueno”).
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Based on Petitioner’s arguments set forth in its Rehearing Request, we
are persuaded that we misapprehended Petitioner’s challenge to independent
claim 1.
With respect to the claimed frame decryption function recited in
independent claim 14, Petitioner argues that it “is satisfied by the inverse
process of decrypting the selectively-encrypted video of claim 1, using the
encryption parameters that, as explained above, identify the layout and offset
of encrypted portions within each frame.” Reh’g Req. 9. According to
Petitioner, the “Petition explained that the prior art encryption parameters
were used as frame decryption information,” which “includes key numbers
and encryption parameters that identify the applicable frame encryption key
and the specific portions of each frame that are encrypted, respectively, for
each encrypted frame.” Id. at 10 (citing Pet. 39, 76) (emphasis omitted).
Petitioner asserts that “[e]ncryption parameters for granularity, density scale,
density, and delay control the partial encryption process and identify the
specific portions of the frames that are encrypted—and thus need to be
decrypted.” Id. (citing Pet. 77) (emphasis omitted).
In our Decision, we determined that Petitioner’s challenge to claim 14
was deficient for substantially the same reasons set forth with respect to
independent claim 1. Dec. 20–21. We determined that, even assuming
Petitioner proposed to construe frame decryption function as a complement
to frame encryption function, Petitioner’s challenge to independent claim 14
was deficient because we understood Petitioner to rely on conventional
encryption algorithms alone. Id. We further determined that Petitioner did
not provide any construction for frame decryption function that
encompassed conventional encryption algorithms alone. Id.
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We now understand Petitioner’s position to similarly concern a two-
step process––the identified encrypted portions are provided as input to a
conventional, symmetric encryption algorithm and both steps together,
according to Petitioner, teach the claimed frame decryption function. See
Pet. 78 (citing Ex. 1004, 1:16–20; Ex. 1005, 6:52–56; Ex. 1006, 27:65–28:1;
§§ VI.A.1, VI.A.5 (claim 4); Ex. 1003 ¶ 257) (“For example, the references
teach using symmetric algorithms for decrypting the selected portions of
encrypted frames in accordance with the frame decryption information
. . . .”).
Based on Petitioner’s arguments set forth in its Rehearing Request, we
are persuaded that we misapprehended Petitioner’s challenge to independent
claim 14. We preliminarily determine that the claimed frame decryption
function is the inverse of the frame encryption function and encompasses
“specifying the location, by layout or offset, of a portion in a frame to which
decryption is applied and the pattern of application of each layout or offset
with respect to each type of frame in a set of frames,” for the reasons
discussed in Section IV.B.2.
For the reasons that follow, we grant Petitioner’s Rehearing Request
and modify our Decision such that we institute an inter partes review with
respect to all challenged claims on the ground set forth in the Petition.
IV. ANALYSIS
A. Asserted Ground of Unpatentability
Petitioner challenges claims 1–6, 9, 10, and 13–19 under 35 U.S.C.
103(a) as being unpatentable over Ueno, Fetkovich, and Demos. Pet. 8. We
maintain our determinations with respect to the level of ordinary skill in the
art from our Decision. Dec. 12.
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B. Claim Construction
1. Frame encryption function
We preliminarily concluded that the claim term frame encryption
function requires specifying the location, by layout or offset, of a portion in
a frame to which encryption is applied and the pattern of application of each
layout or offset with respect to each type of frame in a set of frames. Dec. 9.
Based on the current record and for the purposes of institution, we maintain
that construction.
2. Frame decryption function
The Petition does not propose a claim construction for this term (see
generally Pet.) but argues that “the references teach using symmetric
algorithms for decrypting the selected portions of encrypted frames in
accordance with the frame decryption information” (see id. at 78 (citations
omitted)). The Petition primarily relies on its showing for the frame
encryption function, recited in claim 1, to teach or suggest the frame
decryption function recited in claim 14. See, e.g., id. at 76. In our Decision,
we determined that,
Like the frame encryption function recited in claim 1, the record
does not contain evidence that frame decryption function is a
term of art. The term frame decryption function is not mentioned
in the detailed description portion of the ’673 patent. See
generally id. The record also does not contain evidence that
would tend to support the conclusion that the frame decryption
function performs the inverse of the frame encryption function,
or is the complement of the frame encryption function.
Dec. 11.
On the current record, we are persuaded we misapprehended
Petitioner’s implicit claim construction argument––like with the claimed
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frame encryption function, the frames and portions of those frames to be
decrypted are specified by encryption parameters and provided as input to a
conventional encryption algorithm. Reh’g Req. 10 (citing Pet. 76–77). In
Petitioner’s challenge, the encryption parameters are the same for encryption
and decryption. See id. at 10–11. Petitioner identifies, in part, symmetric
encryption algorithms to teach both the claimed frame encryption function
and the claimed frame decryption function. On the current record, we are
persuaded this is possible because the same key is used to encrypt and
decrypt in symmetric algorithms. Ex. 1003 ¶ 115; Ex. 1001, 3:30–33.
Accordingly, we determine frame decryption function encompasses
“specifying the location, by layout or offset, of a portion in a frame to which
decryption is applied and the pattern of application of each layout or offset
with respect to each type of frame in a set of frames.”
We remind the parties that our claim construction at this stage of the
proceeding is preliminary. Our ultimate interpretation of the claim terms
will be based on the complete record developed during trial.
C. Independent Claim 1
“A method for producing a protected stream of
compressed video content, said method comprising:
receiving an input stream of compressed video
content containing a sequence of frames;”
Petitioner contends that Ueno, Fetkovich, and Demos each
individually teach the subject matter of the preamble. Pet. 29. In relevant
part, Petitioner contends “Ueno teaches a method for encrypting content and
creating a stream of protected data frames.” Id. (citing Ex. 1004, code (57),
1:33–43, 2:50–67, 5:15–32, 6:54–59); see id. (citing Ex. 1005, 1:16–19,
6:49–65, 7:8–27, Fig. 2; Ex. 1006, 21:20–22, Fig. 13) (discussing how
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Fetkovich and Demos each teaches the preamble). On the current record, we
determine that the cited portions of Ueno, Fetkovich, and Demos each
individually teach protecting data by encryption, and the cited portions of
Fetkovich and Demos teach compressed video content.
With respect to the “receiving” limitation, Petitioner further contends
that “Demos and Fetkovich teach receiving an input stream of compressed
video content (such as MPEG) containing a sequence of frames, in order to
encrypt it.” Id. at 29–30 (citing Ex. 1005, 3:4–14, 6:49–57, Fig. 1; Ex. 1006,
21:10–13, 21:20–22, 22:29–39, 23:30–24:19; Ex. 1003 ¶¶ 146–149).
On the current record, having reviewed the cited portions of Ueno,
Fetkovich, and Demos, we are persuaded that the combination sufficiently
supports Petitioner’s contentions regarding the preamble and the “receiving”
limitation.5
“generating a frame encryption key and storing the
encryption key in a key table;”
Petitioner contends that Demos and Fetkovich each individually teach
generating a key to encrypt frames. Pet. 30–31 (citing Ex. 1005, 6:49–52,
Fig. 1; Ex. 1006, 28:1–9, Fig. 13; Ex. 1003 ¶ 150). Petitioner cites Ueno as
teaching storing an encryption key in a key table. Id. at 31. A cited portion
of Ueno discloses “the transmitter 1 and the receiver 2 have identical cipher
key tables 12 and 23, respectively, each having a plurality of cipher keys.”
Ex. 1004, 1:53–55.

5 We need not determine whether the preamble is limiting because Petitioner
sufficiently demonstrates that the references teach the subject matter recited
therein.
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On the current record, having reviewed the cited portions of Ueno,
Fetkovich, and Demos, we are persuaded that the combination sufficiently
supports Petitioner’s contentions regarding the “generating” limitation.
“creating a set of encrypted frames by encrypting at
least selected portions of selected frames of said
sequence of frames using the frame encryption keys
in accordance with a frame encryption function;”
First, Petitioner contends a person of ordinary skill in the art
(POSITA) would have been motivated to select certain frames to encrypt, as
taught by Demos, and “partially encrypt portions of those frames, as taught
by Fetkovich (see [Petition] §VI.A.1 (‘Partial Encryption’)), resulting in the
encryption of selected portions of selected frames.” Pet. 33 (citing Ex. 1003
¶ 154; Ex. 1005, 4:37–44; Ex. 1006, 22:29–58, 23:8–24:18, Fig. 11).
Petitioner further contends that each of Demos, Fetkovich, and Ueno teaches
encryption algorithms. Id. at 34–35. Petitioner also contends that
“Fetkovich teaches encryption algorithms and encryption parameters
together control the encryption process, including the portions of the video
stream to encrypt.” Id. at 35 (citing Ex. 1005, 3:4–14, 5:9–6:40; Ex. 1003
¶ 161) (emphasis added).
Second, Petitioner alternatively asserts
Demos by itself teaches or suggests the creation of a set of
encrypted frames by encrypting at least selected portions (e.g.,
DC coefficients or AC coefficients) of selected frames (e.g.,
I-frames, or I and P-frames) of said sequence of frames using the
frame encryption keys in accordance with a frame encryption
function (e.g., using DES, Triple DES, or Blowfish to encrypt
selected portions of selected frames).
Pet. 35 (citing Ex. 1003 ¶¶ 162–169).
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1. Rationale for Combining
As rationale for combining the teachings of Ueno and Fetkovich,
Petitioner contends that
A POSITA would have been motivated to interleave Ueno’s key
number with Fetkovich’s encryption parameters into the video
stream, including for each video frame. This would have
furthered Fetkovich’s goal of dynamically varying encryption
parameters “based on data content” by allowing changes on a
per-frame basis.
* * *
It would also have furthered Fetkovich’s goal of dynamically
changing encryption parameters by simplifying decryption—the
parameters necessary to decrypt each frame are stored alongside
their associated frames, making it easy to locate or recover the
parameters when they are needed.
Pet. 20, 22 (citing Ex. 1005, code (57), 2:25–31, 3:7–9; 6:57–61; Ex. 1004,
1:37–42, Figs. 4, 6, 17; Pet. §§ V I.A.2[1f-1g]; Ex. 1003 ¶¶ 115, 120–121).
Petitioner offers the testimony of Dr. Patrick McDaniel, who testifies
that “Fetkovich contemplates potential issues where due to data loss, the
receiver’s ‘decryption mechanism may now be out of synchronization with
the transmitter’s encrypter.’” Ex. 1003 ¶ 123 (quoting Ex. 1005, 7:35–40).
He further testifies that “Ueno teaches periodically multiplexing key
numbers into the video stream, including for each frame, which indicates to
the receiver which key should be used for decryption.” Id. ¶ 124 (citing
Ex. 1004, 1:32–42, 2:5–9, 4:46–59, 6:54–59, Figs. 2, 5, 16). Thus,
according to Dr. McDaniel, “[p]eriodically sending the number can provide
synchronization between the transmitter and receiver if it has been lost,”
particularly because “Ueno teaches sending a key number at the front of
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every frame, which would automatically restore synchronization with every
frame.” Id. (citing Ex. 1004, 2:5–9).
With respect to adding Demos to the combination, Petitioner contends
A POSITA would further have been motivated to apply
Fetkovich’s partial encryption teachings to selected frames,
rather than every frame. Fetkovich teaches “an MPEG stream
may be transmitted using varying levels of encryption depending
upon the sensitivity of the video material.” Similarly, Demos
teaches that “to protect a work commercially, not every unit need
by [sic] encrypted or confounded by the encryption of a higher-
level unit. For example, a film may be rendered worthless to
pirates if every other minute of film frames or particularly
important plot or action scenes are encrypted or confounded.” A
POSITA would have been motivated to apply these teachings
from Demos, for example because it provides a teaser/preview
that allows anyone to watch unimportant portions, with an
incentive to pay to unlock the full content. Partially encrypting
every other minute provides sufficient frustration to confound
unauthorized users and incentivize paying for content. Both
provide substantial content protection with reduced
computational requirements.
Pet. 24–25 (citing Ex. 1003 ¶¶ 128, 129; Ex. 1005, 4:30–63; Ex. 1006,
22:29–44) (emphasis omitted).
Having reviewed Petitioner’s contentions and the cited portions of
Ueno, Fetkovich, and Demos, we are persuaded that Petitioner’s rationale
for combining these references is supported by sufficient rational
underpinning and separately, that there is a reasonable expectation of
success in achieving the combination. See id. at 27–28.
2. Patent Owner’s Contentions
First, Patent Owner disputes that the limitation “in accordance with a
frame encryption function” is met by a “standard transformation algorithm”
such as DES, Triple DES, or Blowfish. Prelim. Resp. 26 (citing Pet. 33, 35,
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76–78). Patent Owner supports its contention by arguing that the
Specification of the ’673 patent discloses the DES encryption
transformation, referring to it as a transformation, not as a frame encryption
function. Id. at 26–27 (citing Ex. 1001, 3:27–33).
Second, Patent Owner contends that even assuming, arguendo,
Fetkovich teaches granular encryption, the ’673 patent “discloses in detail
that the layout and ‘offset’ that determines the start of the encrypted portion
within a partially encrypted frame can be based on a function, such as the
Fibonacci series or a non-linear function.” Id. at 30–31 (citing Ex. 1001,
8:5–18) (emphasis added).
Third, Patent Owner contends that even assuming, arguendo, Demos
teaches partial encryption, “Demos . . . does not provide any ‘function’ to
determine the layout of the encrypted portion within the frames in a video
stream.” Id. at 32 (citing Ex. 1001, Fig. 9) (emphasis added).
Fourth, Patent Owner contends that “Petitioner does not even attempt
to prove that ‘frame encryption function’ has an ordinary and customary
meaning to the POSITA in the art.” Id. at 33.
3. Discussion of Patent Owner’s Contentions
With respect to Patent Owner’s first contention, we are persuaded, on
rehearing, that Petitioner does not rely on conventional encryption
algorithms alone to teach the claimed “frame encryption function.” Instead,
Petitioner relies on the combination of selecting which frames to encrypt as
taught by Demos, selecting which portions of the frames to encrypt as taught
by Fetkovich, and providing the selected portions of the selected frames as
input to a conventional encryption algorithm as taught by each of Ueno,
Demos, and Fetkovich, for the reasons discussed above. Supra § III. On the
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current record, we are persuaded that the Petition supports Petitioner’s
rehearing arguments, and that the cited portions of the references sufficiently
support Petitioner’s contentions in the Petition, as discussed below.
With respect to Patent Owner’s second and third contentions, we note
that Petitioner relies on the combination of the selection process in Demos
alone or Demos and Fetkovich and a conventional encryption algorithm to
teach the claimed frame encryption function––the current record does not
support the finding that frame encryption function excludes a combination
that includes conventional encryption algorithms. We note, however, that
the ’673 patent “discloses encryption algorithms, such as DES and
Advanced Encryption Standard (AES), independently of the disclosures and
discussion of frame encryption function and encryption layout approach,” as
we determined in our Decision. Dec. 9 (citing Ex. 1001, 8:26–35). The
parties are invited to address this issue and in particular, this quoted
disclosure of the ’673 patent.
With respect to Patent Owner’s fourth contention, we are not
persuaded that Petitioner’s challenge is deficient for failing to propose a
customary or ordinary meaning for the claim term frame encryption
function.
4. Discussion of Petitioner’s Contentions
Petitioner asserts “Fetkovich teaches encryption parameters to select
which slices or macroblocks in a frame are encrypted, including ‘encryption
granularity, an encryption density scale, an encryption density, an encryption
delay . . . .’” Pet. 33 (citing Ex. 1005, 3:4–14, 5:38–56, 6:24–40; Ex. 1003
¶¶ 155–56). As an example, Fetkovich discloses encrypting every fourth
slice after waiting a delay of one slice. Ex. 1005, 6:34–39. On the current
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record, we are persuaded that this disclosure sufficiently teaches specifying
the location, by layout or offset, of a portion in a frame to which encryption
is applied. Petitioner asserts that Demos teaches selecting which frames are
encrypted: “(1) I and P frames; (2) every other minute of video frames; or
alternatively, (3) frames of particularly important plot or action scenes.”
Pet. 33–34 (citing Pet. § VI.A.1; Ex. 1006, 22:29–44, Fig. 11).
Demos discloses that “a film may be rendered worthless to pirates if
every other minute of film frames or particularly important plot or action
scenes are encrypted or confounded,” that “encryption of the first I frame
confounds all P and B frames derived from that I frame,” and that encrypting
a P-frame within a group of pictures (GOP) will confound the remainder of
the GOP. Ex. 1006, 22:41–44, 22:56–58, Table 7. It is not clear to us how
the cited portions of Demos support Petitioner’s contentions with respect to
I- and P-frames. Dr. McDaniel testifies that “[a] POSITA would have
recognized that encrypting both I and P frames increases security beyond
encrypting only I frames.” Ex. 1003 ¶ 163. Even assuming, arguendo,
Demos only discloses encrypting I-frames or P-frames and not both, that is
sufficient to persuade us that Demos teaches specifying the pattern of
application of each layout or offset with respect to each type of frame in a
set of frames, on the current record.
With respect to Petitioner’s alternative position, Demos teaches
applying encryption to DC and AC coefficients of a frame, in addition to
selecting which frames to encrypt, e.g., I- or P-frames, and in accordance
with methods (2) and (3) above. Ex. 1006, Table 7, Table 8, 22:29–44. On
the current record, we are persuaded that the cited portions of Demos also
teach specifying the location, by layout or offset, of a portion in a frame to
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which encryption is applied, in addition to the pattern of application of each
layout or offset with respect to each type of frame in a set of frames, as set
forth in the preceding paragraph.
We are also persuaded that each of Fetkovich, Ueno, and Demos
individually teaches encrypting using a conventional encryption algorithm.
See Ex. 1004, 1:13–20; Ex. 1005, 6:49–65; Ex. 1006, 27:58–28:7.
Accordingly, we are persuaded that both Demos alone and the
combination of Demos and Fetkovich teach the claimed “frame encryption
function” and the “creating” limitation, on the current record.
“generating frame decryption information
necessary to decrypt said set of encrypted frames
including an encryption key pointer identifying a
decryption key to be used in the decryption of each
encrypted frame; and”
According to Petitioner, Ueno and Fetkovich both teach generating
frame decryption information and then multiplexing that information into a
video stream. Pet. 40–42. Petitioner also contends that “[a] POSITA would
have understood Ueno’s key numbers and Fetkovich’s encryption
parameters to be frame decryption information because they are used to
control the decryption process and are necessary for decrypting video
frames.” Id. at 42–43 (citing Pet. §§ VI.A.2[1d], VI.A.1). Petitioner further
contends that “[w]ith symmetric encryption, a POSITA would have
understood the prior art teachings of key numbers and encryption parameters
to be both frame encryption information and frame decryption information.”
Id. at 43 (citing Ex. 1003 ¶ 177).
More particularly, Petitioner asserts “Ueno further teaches ‘a cipher
key number sending section’ that generates key numbers (e.g., ‘N(ks)’),
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which are periodically transmitted to the receiver, multiplexed into the data
stream, to facilitate decryption of the data stream by identifying the key to
be used for decrypting each portion of the data stream.” Id. at 40 (citing
Ex. 1004, 1:32–42, Fig. 16); see id. at 41 (citing Ex. 1004, 4:46–59, 6:54–
59, Figs. 2, 5; Ex. 1003 ¶ 171). Petitioner further asserts that “Ueno’s
multiplexed key numbers are encryption key pointers that identify a
decryption key to be used in the decryption of each encrypted frame; each
key number identifies a decryption key.” Id. (citing Ex. 1004, 1:53–57,
5:14–20; Ex. 1003 ¶ 172; Pet. § VI.A.1 (explaining Ueno’s teachings
regarding frames)); see id. (citing Ex. 1004, 1:43–60, 4:60–5:3, 5:32–44,
6:60–67).
A cited portion of Ueno discloses “the transmitter 1 and the receiver 2
have identical cipher key tables 12 and 23, respectively, each having a
plurality of cipher keys, and only the cipher key number corresponding to
the cipher key which is used to encipher the transmit data is transmitted to
the receiver 2.” Ex. 1004, 1:53–57 (emphasis added). Ueno further
discloses that “[t]he receiving side decodes the received data to acquire the
cipher key number, and obtains the same cipher key as used at the
transmitting side from the cipher key number to decipher the enciphered
data.” Id. at 1:57–61.
We are further persuaded that Ueno’s teachings relating to cipher key
numbers sufficiently teach the claimed encryption key pointer, that frame
encryption information is the same as frame decryption information in
symmetric encryption algorithms, and both Ueno alone and the combination
of Fetkovich and Ueno teach the claimed “generating” limitation, on the
current record.
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“assembling at least said set of encrypted frames,
unencrypted frames of said sequence of frames, and
said frame decryption information to produce the
protected stream of compressed video content;”
Petitioner contends “Ueno teaches assembling the sequence of frames
and key numbers by multiplexing them into a single protected stream.”
Pet. 43 (citing Ex. 1004, 1:67–2:9). Petitioner further contends “Fetkovich
further teaches assembling the sequence of frames—including encrypted and
unencrypted frames—and the frame decryption information by multiplexing
them into a single stream.” Id. at 45 (citing Ex. 1005, 6:49–65, 7:8–27,
5:34–56, 6:6–7, Fig. 1). According to Petitioner “[a] POSITA would have
been motivated to multiplex key numbers and encryption parameters into the
video stream, as Ueno and Fetkovich teach,” and “would have recognized
Ueno’s key number and Fetkovich’s encryption parameters to be frame
decryption information.” Id. at 46 (citing Pet. §§ VI.A.1, VI.A.2[1e];
Ex. 1003 ¶ 181).
Having reviewed the cited portions of Ueno and Fetkovich we are
persuaded that the combination sufficiently supports Petitioner’s contentions
regarding the “assembling” limitation.
“wherein said frame decryption information is
synchronized with said set of encrypted frames into
a synchronized frame decryption stream.”
Petitioner contends “Ueno further teaches that frame synchronization
signals are used to maintain synchronization of the frames, and that key
numbers are embedded into the video stream following the synchronization
signal, but before the frame.” Pet. 47 (citing Ex. 1004, 1:67–2:9; Fig. 17).
Petitioner further contends “Fetkovich teaches the importance of
maintaining ‘synchronization’ for the frame decryption process.” Id. at 48
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(citing Ex. 1005, 7:35–50). According to Petitioner, “[l]ike Ueno, Fetkovich
teaches using a ‘signal’ to maintain the synchronization of the frame
decryption information (e.g., encryption parameters) with the sequence of
frames.” Id. (citing Ex. 1005, 7:55–67 (“A mechanism for determining that
encryption/decryption synchronization has been lost might be to place a
signal in the first unit of encryption (whether encrypted or not) after a key
change . . . .”); Ex. 1003 ¶ 184).
5. Patent Owner’s Contention
Patent Owner contends that “the synchronized frame decryption
stream must provide decryption information for every encrypted frame so as
to form a ‘stream,’ with the decryption information synchronized with a
corresponding encrypted frame so as to provide the frame’s decryption
information.” Prelim. Resp. 34. According to Patent Owner, “at most, Ueno
discloses that it is merely possible, although not usual, to transmit the key
number with each frame. That does not teach transmission of the key
number with each frame.” Id. at 38 (citing In re Facebook, Inc., 743 Fed
Appx. 998, 1001–02 (Fed Cir. 2018)).
6. Discussion
We are not persuaded by Patent Owner’s contention because, as
Patent Owner notes, Ueno discloses transmitting frame decryption
information, in the form of key numbers, with every encrypted frame. See
Prelim. Resp. 38 (citing Ex. 1004, 2:5–9 (“in some cases, the cipher key
number is transmitted at the start of data communication or at regular
intervals, or is transmitted with each of frames”)).
The analysis and holding in In re Facebook does not support Patent
Owner’s contention about Ueno’s disclosure. In that case,
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The sole question on appeal [was] whether [the cited
reference] Perrodin disclosed “a rule requiring the image
elements to be contiguous such that each available image
position between the first image element in the sequence and the
last image element in the sequence is occupied by an image
element” within the meaning of the claims. It did not. Nothing
about Perrodin’s algorithm required contiguity. It is true that the
example depicted in Figures 18 and 19 happened to result in
contiguity. But that cannot represent a general rule that would
demand contiguity for all images, as required by the claims here
. . . Perrodin’s algorithm could not guarantee contiguity.
Facebook, 743 Fed Appx. at 1001–02. The cited disclosure in Ueno does
not suggest that a cipher key being “transmitted with each frame” is by
happenstance. Instead, the cited portion is an express disclosure of one
frequency option of several frequency options for transmitting a cipher key.
A cited portion of Ueno discloses “the data transmitted onto
transmission line 3 from the transmitter 1 consists of input data D
enciphered by the data enciphering section 11, the cipher key number N(ks)
output from the cipher key number sending section 14 and multiplexed at the
multiplexing section 15, and frame synchronizing signals F.” Ex. 1004,
1:67–2:5. A cited portion of Fetkovich discloses that “the encrypted MPEG
stream is fed to a data multiplexer 24 which multiplexes into the stream the
encryption key employed to encrypt the stream and the encryption
parameters employed by the encryption unit.” Ex. 1005, 6:57–61.
Fetkovich further discloses that some portions are unencrypted. Id. at 6:34–
38 (“One fourth of the slices (256/1024) (i.e., every fourth slice) will be
encrypted” and “the first slice will be unencrypted; encryption will begin
with the second slice (delay of 1) and continue with every fourth slice
thereafter.”). We are persuaded that both Ueno and Fetkovich disclose
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synchronizing, on the current record. See Ex. 1004, 1:67–2:9 (“[D]ata
transmitted . . . consists of input data D . . . the cipher key number N(ks) . . .
multiplexed at the multiplexing section 15, and frame synchronizing signals
F.”); Ex. 1005, 7:55–67 (“A mechanism for determining that
encryption/decryption synchronization has been lost might be to place a
signal in the first unit of encryption (whether encrypted or not) after a key
change.”); Ex. 1003 ¶ 184.
On the current record, we are persuaded that the cited teachings of
Ueno and Fetkovich, either individually or in combination, teach the claimed
“synchronizing” limitation.
For the foregoing reasons, we are persuaded that Petitioner’s
contentions are sufficiently supported by the cited art and thus, demonstrate
a reasonable likelihood of prevailing with respect to unpatentability of
claim 1 over the combination of Ueno, Fetkovich, and Demos.6
D. Independent Claim 14
Independent claim 14 recites similar features to independent claim 1,
except claim 14 concerns decryption instead of encryption. Patent Owner
addresses claims 1 and 14 together. See generally Prelim. Resp. Our
analysis with respect to claim 14 is substantially similar to our analysis with
respect to claim 1 and for these reasons, we are persuaded that Petitioner’s
contentions are sufficiently supported by the cited art and thus, demonstrate
a reasonable likelihood of prevailing with respect to claim 14.

6 At this stage of the proceeding, neither party has presented evidence of
objective considerations of nonobviousness.
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E. Dependent Claims 2–6, 9, 10, and 13, and 15–19
As to the remaining claims 2–6, 9, 10, 13, and 15–19 asserted in the
Petition, Patent Owner does not raise any arguments. See generally Prelim.
Resp. Having decided that Petitioner is likely to prevail as to at least one
claim challenged in the Petition, independent claims 1 and 14, the review
shall proceed on all challenged claims and on the ground raised in the
Petition.
V. DISCRETION
According to Petitioner,
Two of the three references for Ground 1—Ueno and Demos—
were not before the examiner, nor were they similar to or
cumulative of Nardone, the only reference other than Fetkovich
used for rejections. Ex. 1001, 1; Ex. 1002. Nardone lacks
relevant teachings from Ueno and Demos, including selective
video encryption based on AC/DC coefficients or important
action scenes, key tables, key numbers, and assembling key
numbers with video frames in a synchronized manner. See §§
VI.A.2[1d-1g]; Ex. 1003 ¶92. The Petition relies on Ueno’s key
number teachings for limitations including “a reference to a
decryption key in the key table” (claim 4), rather than anything
in Fetkovich.
Pet. 14 (citing Pet. §§ VI.A.2[1e-1g], VI.A.3, VI.A.5).
With respect to Fetkovich and Ueno, Patent Owner contends
“Petitioner relies on Fetkovich for the very limitation that was rejected and
subsequently allowed by the Examiner in view of Fetkovich—adding
nothing but an inconsequential additional reference, Ueno.” Prelim. Resp. 5
(citing Prelim Resp. § II.B). Patent Owner adds that “Ueno does not
substantively change the deficiencies in Fetkovich,” asserting that it is
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cumulative to Fetkovich, and also does not disclose a “frame decryption
stream.” Id. at 5, 11.
With respect to Demos, Patent Owner contends that the Petition does
not rely on Demos for many limitations, and in particular, “does not assert
that Demos discloses the limitation of ‘frame decryption stream,’” which
Patent Owner contends “is the very limitation that was added by Examiner
amendment before the claims were allowed over Fetkovich.” Id. at 9–10.
Thus, Patent Owner contends that “Demos is at most cumulative to
Fetkovich” and that “[t]he Petition relies on Demos for the alleged
disclosure of partial encryption of selected frames.” Id. at 10.
In additional pre-institution briefing, Petitioner argued that “[t]he
Examiner also erred by overlooking specific teachings of Fetkovich,
including its ‘granularity’ and ‘delay’ parameters, which provide the
encryption offset that DivX contends is missing in the prior art.” Prelim.
Reply 7 (citing Ex. 1005, 3:4–14, 5:9–6:40; Advanced Bionics, LLC v.
MED-EL Elektromedizinische Geräte GmbH, IPR2019-01469, Paper 6 at 8–
9, n.9 (PTAB Feb. 13, 2020) (precedential)). Patent Owner disputes this
point, arguing that the Examiner considered these teachings of Fetkovich in
column 7, cited during prosecution and in the Petition. Prelim. Sur-reply, 2–
3.
Institution of inter partes review is discretionary. See Harmonic Inc.
v. Avid Tech, Inc., 815 F.3d 1356, 1367 (Fed. Cir. 2016) (“[T]he PTO is
permitted, but never compelled, to institute an IPR proceeding.”); 35 U.S.C.
§ 314(a). Pursuant to 35 U.S.C. § 325(d), in determining whether to institute
an inter partes review, “the Director may take into account whether, and
reject the petition or request because, the same or substantially the same
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prior art or arguments previously were presented to the Office.” In
evaluating arguments under § 325(d), we use
[a] two-part framework: (1) whether the same or substantially
the same art previously was presented to the Office or whether
the same or substantially the same arguments previously were
presented to the Office; and (2) if either condition of first part of
the framework is satisfied, whether the petitioner has
demonstrated that the Office erred in a manner material to the
patentability of challenged claims.
Advanced Bionics, IPR2019-01469, Paper 6 at 8; see also Becton, Dickinson
& Co. v. B. Braun Melsungen AG, IPR2017–01586, Paper 8 at 17–18
(PTAB Dec. 15, 2017) (precedential as to Section III.C.5, first paragraph)
(listing factors to consider in evaluating the applicability of § 325(d)).
Because we determine that the same or substantially the same art or
arguments were not previously presented to the Office, we need not reach
the second part of the Advanced Bionics framework.
We begin our analysis with the first part of the Advanced Bionics
framework. In the first part of the framework, we look to Becton, Dickinson
factors (a), (b), and (d) to evaluate “the similarities and material differences
between the asserted art and the prior art” previously presented to the Office
during a proceeding pertaining to the challenged patent (factor (a)), “the
cumulative nature of the asserted art and the prior art evaluated” previously
(factor (b)), and “the extent of the overlap between the arguments”
previously presented “and the manner in which petitioner relies on the prior
art” (factor (d)). Advanced Bionics, Paper 6 at 9 n.10 (citing Becton,
Dickinson, Paper 8 at 17–18); see id. at 9–10.
The Petition presents one ground of unpatentability based on Ueno,
Fetkovich, and Demos against the challenged claims. See Pet. 8. Both
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Petitioner and Patent Owner acknowledge that Fetkovich was cited and
applied by the Examiner in a rejection. See Pet. 13–14; Prelim. Resp. 4–5;
Advanced Bionics, Paper 6 at 7–8. However, Ueno and Demos were never
cited during the prosecution of the ’673 patent. The teachings of Ueno and
Demos set forth in the Petition are not cumulative to the teachings of the art
evaluated by the Examiner during prosecution of the ’673 patent, contrary to
Patent Owner’s contentions, for the reasons discussed below. Because the
challenge set forth in the Petition is in combination with Ueno and Demos,
which were not considered by the Examiner, we find that consideration of
the references and arguments based thereon to be materially different than
the Examiner’s previous consideration of Fetkovich.
In an Office Action dated January 11, 2007, the Examiner found
Fetkovich taught
[D]ynamic decryption of stream of data wherein decrypting the
dynamically varied encrypted stream of data (that may comprise
MPEG compressed video). Fetkovich discloses forwarding
encrypted stream to a decryption unit wherein, recognizing
encrypted frames (containing encryption key, key update unit,
and other encryption parameter) and using the encryption
information, providing an unencrypted MPEG stream.
Ex. 1002, 79 (citing Ex. 1005, 7:2–21). In a responsive Amendment dated
April 19, 2007, Patent Owner amended the claims to additionally recite,
among other things “generating a frame encryption key and including the
encryption key in a table of encryption keys,” and “wherein said frame
decryption information is synchronized with said set of encrypted frames.”
Id. at 92. Thereafter, a Notice of Allowance issued on July 13, 2007, in
which the Examiner found that
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the admitted prior arts [Nardone and Fetkovich] taken
independently or in combination, do not disclose, teach or
suggest “creating a set of encrypted frames by encrypting at least
selected portions of selected frames of said sequence of frames
using the frame encryption keys in accordance with a frame
encryption function; generating frame decryption information
necessary to decrypt said set of encrypted frames including an
encryption key pointer identifying a decryption key to be used in
the decryption of each encrypted frame; and assembling at least
said set of encrypted frames, unencrypted frames of said
sequence of frames, and said frame decryption information to
produce the protected stream of compressed video content;
wherein said frame decryption information is synchronized with
said set of encrypted frames into a synchronized frame
decryption stream[.]”
Id. at 141 (emphasis added). The Notice of Allowance was accompanied by
an Examiner’s Amendment that added, among other things, the limitation
reciting “generating frame decryption information . . . including an
encryption key pointer identifying a decryption key to be used in the
decryption of each encrypted frame.” Id. at 142.
Ueno is cited to teach the claimed encryption key pointer, a limitation
that the Examiner expressly found to be missing in the combination of
Nardone and Fetkovich. Pet. 41. This is the dispositive issue––not whether
the same portion of Fetkovich cited during prosecution was relied on in the
Petition, and not whether Demos is cited for “enough” limitations. See
Prelim. Resp. 9–10. We are further unpersuaded by Patent Owner’s
argument with respect to the claimed “synchronized frame decryption
stream.” Id. at 3–4. As noted above, the Examiner cited several limitations
in the reasons for allowance of which “synchronized frame decryption
stream” was only one.
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The Examiner indicated a subset of the combination of features
recited in amended independent claim 1 in the Reasons for Allowance
section. See Ex. 1002, 140–42. Ueno is not cumulative to the references
considered and applied during prosecution of the ’673 patent because it is
cited, in Petitioner’s challenges, to teach one of the limitations in the subset
of limitations that led to allowance, i.e., “including an encryption key pointer
identifying a decryption key to be used in the decryption of each encrypted
frame.”
Accordingly, we do not find that Becton Dickinson factors (a), (b),
and (d) are met for Petitioner’s challenge based, in part, on Fetkovich, and
we find that those grounds of unpatentability do not rely upon the same or
substantially the same prior art or arguments considered during examination
of the ’673 patent. See Oticon Medical AB v. Cochlear Ltd., IPR2019-
00975, Paper 15 at 20 (PTAB Oct. 16, 2019) (precedential) (declining to
exercise discretion when new, noncumulative prior art was asserted in the
Petition). Having failed the first part of the framework under Advanced
Bionics, we need not determine whether Petitioner has demonstrated that the
Office erred in a manner material to the patentability of the challenged
claims. After careful consideration of the record before us, we determine
that, on balance, the totality of the evidence favors declining to exercise our
discretion under 35 U.S.C. § 325(d) to deny institution.
VI. CONCLUSION
For the reasons discussed above, we are persuaded that Petitioner
demonstrates a reasonable likelihood that claims 1 and 14 are unpatentable
as obvious under 35 U.S.C. § 103 over Ueno, Fetkovich, and Demos.
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Accordingly, review shall proceed on claims 1–6, 9, 10, and 13–19 of the
’673 patent on the ground set forth in the Petition.

VII. ORDER
In consideration of the foregoing, it is hereby:
ORDERED that Petitioner’s Request for Rehearing (Paper 12) is
granted;
FURTHER ORDERED that, pursuant to 35 U.S.C. § 314(a), an inter
partes review is instituted in this proceeding with respect to claims 1–6, 9,
10, and 13–19 of the ’673 patent on the ground set forth in the Petition; and
FURTHER ORDERED that, pursuant to 35 U.S.C. § 314(c) and
37 C.F.R. § 42.4(b), inter partes review shall commence on the entry date of
this Decision, and notice is hereby given of the institution of a trial.

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For PETITIONER:
Harper Batts
Chris Ponder
Jeffrey Liang
SHEPPARD, MULLIN, RICHTER & HAMPTON, LLP
hbatts@sheppardmullin.com
cponder@sheppardmullin.com
jliang@sheppardmullin.com

For PATENT OWNER:
Kenneth Weatherwax
Nathan Lowenstein
Bridget Smith
Flavio Rose
Edward Hsieh
Parham Hendifar
Patrick Maloney
Jason Linger
LOWENSTEIN & WEATHERWAX LLP
weatherwax@lowensteinweatherwax.com
lowenstein@lowensteinweatherwax.com
smith@lowensteinweatherwax.com
rose@lowensteinweatherwax.com
hsieh@lowensteinweatherwax.com
hendifar@lowensteinweatherwax.com
maloney@lowensteinweatherwax.com
linger@lowensteinweatherwax.com