  United States Court of Appeals
      for the Federal Circuit
                ______________________

     PERSONAL WEB TECHNOLOGIES, LLC,
                Appellant

                           v.

                    APPLE, INC.,
                       Appellee
                ______________________

                      2018-1599
                ______________________

    Appeal from the United States Patent and Trademark
Office, Patent Trial and Appeal Board in No. IPR2013-
00596.
                 ______________________

                Decided: March 8, 2019
                ______________________

    LAWRENCE MILTON HADLEY, Glaser Weil Fink Howard
Avchen & Shapiro LLP, Los Angeles, CA, argued for appel-
lant. Also represented by JOEL LANCE THOLLANDER,
McKool Smith, PC, Austin, TX.

   MICHAEL JAY, DLA Piper LLP (US), Los Angeles, CA,
argued for appellee.  Also represented by NANDAN
PADMANABHAN.
              ______________________

   Before MOORE, TARANTO, and CHEN, Circuit Judges.
2             PERSONAL WEB TECHNOLOGIES, LLC v. APPLE, INC.




CHEN, Circuit Judge.
    PersonalWeb Technologies, LLC (PersonalWeb) ap-
peals the final written decision of the Patent Trial and Ap-
peal Board (Board) in an inter partes review (IPR)
proceeding concluding that Apple demonstrated by a pre-
ponderance of the evidence that claims 24, 32, 81, 82, and
86 of U.S. Patent No. 7,802,310 (the ’310 patent) are un-
patentable as obvious in view of two prior art references—
U.S. Patent No. 5,649,196 (Woodhill) and U.S. Patent No.
7,359,881 (Stefik). Because one of the Board’s key under-
lying fact findings as to Woodhill’s disclosure is not sup-
ported by substantial evidence, we reverse.
                       BACKGROUND
                    A. The ’310 Patent
     The ’310 patent explains that in conventional data pro-
cessing systems, data items such as files are typically iden-
tified by their user-created alphanumeric name and/or
pathname or location. J.A. 69 at 1:53–2:5. Certain prob-
lems arise, however, using traditional naming conventions.
For example, if one device transfers a data item to a second
device using just the name associated with the data item,
it is possible that the data item already exists on the second
device, and a duplicate of the data item will be created.
J.A. 69–70 at 2:63–3:9. The ’310 patent contemplates a
method and apparatus for resolving this and other con-
cerns by creating a substantially unique identifier for each
data item in the data processing system that is independ-
ent of the data item’s user-defined name, location, etc., but
rather is dependent on only the content of the data item
itself. J.A. 70 at 3:52–58. The identifier for a particular
data item is created by applying a cryptographic hash func-
tion to the data item. J.A. 74 at 12:21–26. The output of
the hash function is the content-based identifier or “True
Name,” which is “virtually guaranteed” to be unique to the
data item. Id. The system uses the content-based identi-
fier alone to determine whether a particular data item is
PERSONAL WEB TECHNOLOGIES, LLC v. APPLE, INC.                3



present on the system. J.A. 70 at 3:59–62. When the data
item’s contents are changed, the content-based identifier of
the data item also changes. See J.A. 86 at 35:55–63.
     The ’310 patent explains that content-based identifiers
can be used for various purposes in data processing sys-
tems, including, for example, to identify data items in a “li-
cense table.” J.A. 74 at 11:33–43. The patent describes a
license table as a two-field database containing a list of con-
tent-based identifiers and, for each content-based identi-
fier, a list of users authorized to access the data item
associated with the content-based identifier. Id.
    Claim 24 is illustrative:
    24. A computer-implemented method implemented
    at least in part by hardware comprising one or
    more processors, the method comprising:
    (a) using a processor, receiving at a first computer
    from a second computer, a request regarding a par-
    ticular data item, said request including at least a
    content-dependent name for the particular data
    item, the content-dependent name being based, at
    least in part, on at least a function of the data in
    the particular data item, wherein the data used by
    the function to determine the content-dependent
    name comprises at least some of the contents of the
    particular data item, wherein the function that was
    used comprises a message digest function or a hash
    function, and wherein two identical data items will
    have the same content-dependent name; and
    (b) in response to said request:
        (i) causing the content-dependent name of
        the particular data item to be compared to
        a plurality of values;
        (ii) hardware in combination with software
        determining whether or not access to the
4               PERSONAL WEB TECHNOLOGIES, LLC v. APPLE, INC.




           particular data item is unauthorized based
           on whether the content-dependent name of
           the particular data item corresponds to at
           least one of said plurality of values, and
           (iii) based on said determining in step (ii),
           not allowing the particular data item to be
           provided to or accessed by the second com-
           puter if it is determined that access to the
           particular data item is not authorized.
J.A. 88.
                   B. Initial IPR Proceedings
     In September 2013, Apple filed a petition requesting an
IPR of claims 24, 32, 70 1, 81, 82, and 86 of the ’310 patent,
asserting multiple grounds of unpatentability. Personal-
Web filed a preliminary patent owner response, and, in
March 2014, the Board instituted review on the ground
that the petition raised a reasonable likelihood that the
challenged claims were unpatentable under 35 U.S.C.
§ 103(a) for obviousness over Woodhill in view of Stefik. Af-
ter PersonalWeb filed a patent owner response and Apple
filed a reply, the Board held a hearing. In March 2015, the
Board issued a final written decision concluding that Apple
had demonstrated by a preponderance of the evidence that
the challenged claims were unpatentable under § 103(a)
over Woodhill in view of Stefik.
                          C. Woodhill
    Woodhill discloses a distributed management system
for backing up and restoring data files. See J.A. 1674 at
1:11–17. In Woodhill, files are apportioned into 1 MB 2


    1   Though part of the IPR process, claim 70 is not be-
fore us on appeal.
    2   The final binary object in the file may be less than
1 MB in size.
PERSONAL WEB TECHNOLOGIES, LLC v. APPLE, INC.               5



“binary objects,” which in some instances are apportioned
even further into 1 KB 3 “granules.” J.A. 1675 at 4:21–30,
J.A. 1677 at 7:47–59, J.A. 1680–81 at 14:65–15:4. Woodhill
explains that the system uses “Binary Object Identifiers,”
or for granules, “contents identifiers,” to determine
whether a binary object or granule has changed from one
version of the file to the next. J.A. 1678 at 9:9–27, J.A.
1682 at 17:50–64. Only those binary objects or granules
whose content has changed need to be backed up, thereby
reducing the amount of data that needs to be transmitted
during a backup procedure. Id. at 9:6–9, 9:23–27, J.A.
1680–81 at 14:53–15:8. Woodhill explains that every new
or changed binary object is backed up onto a remote backup
file server, and that a compressed copy of every binary ob-
ject that the system would need in order to restore a cur-
rent version of a file to a previous version of the file is
stored somewhere on the local area network other than on
the local computer. J.A. 1678 at 9:30–44.
    Woodhill discloses a File Database containing three
levels of records. J.A. 1675 at 3:45–54. At the highest level,
File Identification Records are stored for each file that has
been backed up by the system. Id. at 3:54–56. Each File
Identification Record includes, inter alia, the file’s name
and location. Id. at 3:57–63. At the second level, each File
Identification Record is associated with one or more
Backup Instance Records, each of which contains infor-
mation about a backup version of the file. Id. at 3:64–4:2.
Each Backup Instance Record includes, inter alia, a link to
the File Identification Record. Id. at 4:2–11. At the third
level, each Backup Instance Record is associated with one
or more Binary Object Identification Records (depending
on the size of the file). Id. at 4:12–47. A Binary Object
Identification Record is created for each binary object of the



    3  The final granule in the binary object may be less
than 1 KB in size.
6            PERSONAL WEB TECHNOLOGIES, LLC v. APPLE, INC.




backup file version. Id. at 4:30–34. Each Binary Object
Identification Record includes, inter alia, a link to the
Backup Instance Record, the Binary Object Size, the Bi-
nary Object Offset, and the Binary Object Hash. Id. at
4:35–43.
     The Binary Object Size and the Binary Object Hash,
together with other information not relevant to this appeal,
make up the “Binary Object Identifier” for that version of
the binary object. Id. at 4:43–47. The Binary Object Iden-
tifier is unique to a particular binary object because of the
Binary Object Hash field, which is created by applying a
cryptographic hash algorithm to contents of the binary ob-
ject. J.A. 1677 at 8:22–35. Woodhill explains that the crit-
ical feature of the Binary Object Identifier is that, because
it is based on the contents of the binary object, the identi-
fier changes when the contents of the binary object change.
Id. at 8:58–62. Duplicate binary objects can therefore be
recognized from their identical Binary Object Identifiers
even if they reside on different types of computers in the
same network. Id. at 8:62–65.
                         D. Stefik
    Stefik discloses an authentication system for control-
ling access to digital works. J.A. 1632 at 3:58–4:12. Each
digital work’s unique identifier and associated usage
rights, among other information, are stored in a repository.
J.A. 1635 at 9:15–61. A user accesses a digital work over a
network using a “digital ticket,” which entitles the ticket
holder to exercise usage rights associated with the work
because, for example, the user has paid for access. J.A.
1632 at 3:59–64.
             E. First Federal Circuit Appeal
    PersonalWeb appealed the 2015 Board unpatentability
decision to our court, and on February 14, 2017, we issued
an opinion affirming the Board’s claim construction and va-
cating and remanding the Board’s obviousness finding for
PERSONAL WEB TECHNOLOGIES, LLC v. APPLE, INC.               7



further consideration. See Pers. Web Techs., LLC v. Apple,
Inc., 848 F.3d 987 (Fed. Cir. 2017) (PersonalWeb I). We
noted that none of the parties disagreed that Woodhill’s Bi-
nary Object Identifier corresponded to the claimed content-
based identifier4 for a data item of the ’310 patent. Id. at
991. However, we determined that the Board’s analysis
with respect to obviousness—including both whether
Woodhill and Stefik disclosed all of the elements recited in
the challenged claims and whether a skilled artisan would
have been motivated to combine them in the manner re-
cited in the ’310 patent—was inadequate. Id. at 993.
    The main claim element in dispute in that appeal, as
in this appeal, was claim 24’s “causing the content-depend-
ent name of the particular data item to be compared to a
plurality of values.” Id. The Board had cited only Stefik as
satisfying this element, but Apple made clear in its petition
that it relied on only Woodhill for this element. Id. We
disagreed with the Board’s use of Stefik and instructed the
Board to evaluate whether column 17 of Woodhill, which
was the only portion of Woodhill cited by Apple in its peti-
tion, taught this element. Id. We also disagreed with the
Board’s motivation-to-combine analysis, which merely af-
firmed Apple’s allegation that a skilled artisan “would have
allowed for the selective access features of Stefik to be used
with Woodhill’s content-dependent identifiers feature.” Id.
(emphasis omitted). We explained that this reasoning said
nothing more than that the two references could be com-
bined, not that there would been a motivation to combine
them, and lacked any explanation as to how the



    4   In PersonalWeb I, we used the term “content-based
identifier” to refer to multiple claim terms including “con-
tent-dependent name,” “content-based identifier,” and “dig-
ital identifier,” because no issue before us turned on any
differences between them. Id. at 990. We do the same
here.
8             PERSONAL WEB TECHNOLOGIES, LLC v. APPLE, INC.




combination of the two references was supposed to work.
Id. at 993–94. We remanded for the Board to reconsider
the merits of the obviousness challenge. Id. at 994.
    The Board ordered additional briefing by the parties to
explain where Apple did or did not make a proper case of
obviousness on the instituted ground. J.A. 4.
               F. Board’s Remand Analysis
    On remand, the Board maintained the same obvious-
ness theory of unpatentability, except that the Board re-
placed its previous reliance on Stefik for teaching the
“compared to a plurality of values” element with reliance
on column 17 of Woodhill. J.A. 13–16. The Board also ex-
panded its analysis of a skilled artisan’s motivation to com-
bine Woodhill and Stefik. J.A. 16–18.
    Element (b)(i) of claim 24 is the main point of conten-
tion between the parties. It recites, after “in response to
said request,” “causing the content-dependent name of the
particular data item to be compared to a plurality of val-
ues.” J.A. 88 at 40:15–17. The Board pointed to Apple’s
petition, which cited column 17, lines 40 to 46 of Woodhill:
    Program control then continues with step 446
    where the Distributed Storage Manager program
    448 transmits an “update request” to the remote
    backup file server 12 which includes the Binary
    Object Identification Record 58 for the previous
    version of each binary object as well as the list of
    “contents identifiers” calculated in step 444.
J.A. 14. The Board continued to point to Apple’s petition,
which cited Apple’s expert, and stated: “in order to deter-
mine which data needs to be restored by the update re-
quest, the remote backup file server of Woodhill must be
able to reference its local files using the information it re-
ceives - namely the Binary Object Identification Record.”
Id. (emphasis added) (brackets and internal quotation
marks omitted). The Board then adopted Apple’s expert’s
PERSONAL WEB TECHNOLOGIES, LLC v. APPLE, INC.             9



conclusion that the “referencing necessarily must be accom-
plished” using “the remote backup fileserver,” which
“maintains some sort of file system or other mapping (i.e.,
a database) that allows the Binary Object Identification
Record to serve as a lookup for the requisite file data that
is to be restored.” Id. (emphasis added). The Board there-
fore concluded that Woodhill, without saying so, neces-
sarily compares the content-based identifier (Binary Object
Identifier) of the particular data item (binary object) to a
plurality of values (an unmentioned but necessarily pre-
sent database of Binary Object Identifiers). In other words,
the Board found that Woodhill inherently teaches compar-
ing a Binary Object Identifier to a plurality of Binary Ob-
ject Identifiers.
     As to Stefik, the Board described Stefik as “a system
that addresses the problem of preventing unauthorized ac-
cess to digital works with an access request utilizing a
unique identifier for the digital work.” J.A. 15. The Board
stated that it “agree[d] with Apple that access provided in
Stefik would necessarily require a comparison between the
unique identifier and other values to see if a match can be
obtained,” citing Apple’s expert testimony as support. J.A.
15–16. Apple further contended that “a skilled artisan
would have combined the backup and restore system in
Woodhill with the repository in Stefik to add an authoriza-
tion layer to prevent unauthorized users from accessing a
different user’s back up files.” J.A. 16. The Board con-
cluded that this rationale was sufficient, and that Apple
had demonstrated by a preponderance of the evidence that
the challenged claims were unpatentable under § 103(a) as
obvious over Woodhill and Stefik. J.A. 17–18.
    PersonalWeb appealed both the Board’s inherency
finding and its motivation-to-combine finding. We have ju-
risdiction under 28 U.S.C. § 1295(a)(4)(A).
10           PERSONAL WEB TECHNOLOGIES, LLC v. APPLE, INC.




                        DISCUSSION
     “We review the Board’s ultimate determination of obvi-
ousness de novo and its underlying factual determinations
for substantial evidence.” PersonalWeb I, 848 F.3d at 991.
“On the factual components of the inquiry, we ask whether
a reasonable fact finder could have arrived at the agency’s
decision, which requires examination of the record as a
whole, taking into account evidence that both justifies and
detracts from an agency’s decision.” Id. (internal brackets
and quotation marks omitted).
     We conclude that the Board’s inherency finding derived
from column 17 of Woodhill for teaching the “compared to
a plurality of values” limitation lacks substantial evidence.
While it is possible that Woodhill’s system utilizes an un-
stated Binary Object Identifier lookup table to locate bi-
nary objects of a previous version of a file that is going to
be restored (column 17 of Woodhill), mere possibility is not
enough. “Inherency . . . may not be established by proba-
bilities or possibilities.” PAR Pharm., Inc. v. TWI Pharm.,
Inc., 773 F.3d 1186, 1195 (Fed. Cir. 2014). “The mere fact
that a certain thing may result from a given set of circum-
stances is not sufficient.” Id. (emphasis added). Rather, a
party must “show that the natural result flowing from the
operation as taught would result in the performance of the
questioned function.” Id. (emphasis in original).
    As PersonalWeb suggests, an equally plausible, if not
more plausible, understanding of Woodhill is that
Woodhill’s system uses conventional file names and loca-
tions to locate files and the Binary Object Offset field to
locate a given binary object within a file. Before the pas-
sage relied on by Apple and the Board (lines 40 to 46), col-
umn 17 states that Woodhill’s system “obtains from the
user the identities of the current and previous versions of
the file (comprised of binary objects) which needs to be re-
stored.” J.A. 1682 at 17:28–32 (emphasis added); see also
J.A. 1670 at Fig. 5I (step 442). The next sentence confirms
PERSONAL WEB TECHNOLOGIES, LLC v. APPLE, INC.              11



that the file is “user-specified.” J.A. 1682 at 17:32–35. The
Board’s proffered look-up table is therefore unnecessary to
locate the current or previous version of the file.
    Even if the file was not specified by the user, Woodhill’s
only disclosed method of locating a current or previous file
is by searching for the file using standard file block infor-
mation, including the file name and location. J.A. 1676 at
5:46–6:11. Woodhill does not disclose searching for a file
based on a content-based identifier.
     As to locating binary objects within a file, Woodhill ex-
plains that the system compiles a list of these binary ob-
jects using “information . . . obtained from File Database
25” after the identity of the file is obtained. J.A. 1682 at
17:32–36, J.A. 1670 at Fig. 5I (step 443). Although this
portion of Woodhill’s specification does not specify what ex-
actly in the File Database is used to locate a particular bi-
nary object within a given file, Woodhill explains in column
9 that binary objects can be located within a particular file
using the Binary Object Stream Type field and the Binary
Object Offset field of each Binary Object Identification Rec-
ord. J.A. 1678 at 9:14–22. That disclosure, albeit at a dif-
ferent location in Woodhill’s written description than
column 17, suggests that Woodhill contemplated a means
for locating binary objects that would make Apple and the
Board’s proposed look-up table unnecessary for Woodhill’s
restore process described at column 17. As PersonalWeb
correctly points out, the only disclosed use of Woodhill’s Bi-
nary Object Identifier is to perform a one-to-one compari-
son with the Binary Object Identifier associated with the
backed-up version of the binary object, which occurs after
the appropriate binary object has been located, according
12            PERSONAL WEB TECHNOLOGIES, LLC v. APPLE, INC.




to column 9. Neither Apple nor its expert provided any ad-
equate response to this reading of Woodhill. 5
    Because we find that the proposed, theoretical Binary
Object Identifier look-up table that Apple and the Board
rely on does not necessarily exist in Woodhill, the Board’s
reliance on inherency for that element in its obviousness
analysis was improper. Apple provided no other basis for
this element of comparing a content-based identifier to a
plurality of values being disclosed or otherwise obvious to
a skilled artisan at the time of the invention. We therefore
reverse the Board’s finding of obviousness over Woodhill in
view of Stefik. We need not reach the question of motiva-
tion to combine. We have considered the parties’ remain-
ing arguments and find them unpersuasive.
                       REVERSED




     5   We also note that the binary object look-up table
proffered by Apple and the Board could lead to a peculiar
design if it contained multiple binary objects for every large
file on the system, as Apple’s counsel alleged at oral argu-
ment, thereby requiring a comparison of a particular Bi-
nary Object Identifier to millions of Binary Object
Identifiers not even associated with the correct file. See
Oral Argument at 14:20–15:50 (acknowledging that there
could be ten million Binary Object Identifiers in the look-
up table for a far smaller number of files).
