Ex Parte Wong et al

Board of Patent Appeals and Interferences

Oct 25, 2002

08924867 (B.P.A.I. Oct. 25, 2002)

1
The opinion in support of the decision being entered today was not written
for publication and is not binding precedent of the Board
Paper No. 18
UNITED STATES PATENT AND TRADEMARK OFFICE
_______________
BEFORE THE BOARD OF PATENT APPEALS
AND INTERFERENCES
_______________
Ex parte STEPHEN T. WONG
and JAMES YUAN-PIN YU
______________
Appeal No. 2001-0575
Application 08/924,867
_______________
ON BRIEF
_______________
Before THOMAS, KRASS , and JERRY SMITH, Administrative Patent Judges.
KRASS, Administrative Patent Judge.

DECISION ON APPEAL
This is a decision on appeal from the final rejection of claims 1-3, 5-9, 11-15 and 17-21,
all of the pending claims.
The invention is directed to a digital trust center for medical image authentication. In
particular, systems exist for management of image information including digital images and
associated data by maintaining at least one central electronic archive which may be accessed over
a digital data network. A system known as Picture Archiving and Communications Systems
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(PACS) is used for medical images in association with a digital trust center for enabling
authentication of the image information. In order to protect the confidentiality of the information
and determine the authenticity of digital images, cryptographic techniques have been integrated
with PACS. By employing a digital trust center, an authentication server is provided to attach a
hash value, i.e., a “digital fingerprint,” derived from the image data set to an incoming image
dataset so that the hash is stored with the image data set in the image data store maintained by the
PACS archive server. The PACS archive server can check the authenticity of the image data set
by comparing the stored hash with one it computes from the stored image data set.
In order to reduce vulnerability of such a system to attack or a comprise of authenticity
and security, the invention provides “in association with an image management system, an
authentication and security system comprising an authentication server or so-called “digital trust
center” which maintains and stores hashes and corresponding time stamps indicating the times of
receipt of the respective hashes, and provides them on request in encrypted form, and further
functionality in the image acquisition computers and the display stations to provide for security
and to interact with the authentication server for authentication purposes” [specification-page 4].
Independent claim 1 is reproduced as follows:
1. In an image management system comprising image acquisition computers for
acquiring image information from imaging devices associated with the image acquisition
computers and forming image datasets, each comprising an image header and image data, an
image archive server for receiving the image datasets from the acquisition computers and
maintaining at least one image data store for the image datasets, and a plurality of remote display
stations for displaying images from requested image datasets which are retrieved by the image
archive server from the image data store and sent to the requesting display station, an
authentication and security system comprising:
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an authentication server for maintaining and storing pairs of hashes and identifiers, and
for providing hashes in encrypted form in response to requests from display stations, wherein the
requests include identifiers;
the acquisition computers being configured for pre-processing the image datasets,
including performing any required image compression, encrypting at least a portion of the image
datasets after any such compression, forming identifiers, computing hashes, providing pairs of
hashes and identifiers to the authentication server, and sending pre-processed image datasets to
the image archive server for storage in the image data store; and
the display stations being configured for requesting and receiving identified pre-processed
image datasets from the image archive server, decrypting the image datasets sent by the image
archive server, performing any required data decompression on the image datasets, forming
identifiers from the image datasets, computing hashes from the image datasets, sending requests
including the formed identifiers to the authentication server, receiving identified hashes in
encrypted form from the authentication server, decrypting hashes received from the
authentication server, and comparing the hashes obtained from the authentication server with the
hashes computed locally from the image datasets received from the image archive server.
The examiner relies on the following references:
Fisher et al. (Fisher) 4,833,625 May 23, 1989
Dyson 5,050,212 Sep. 17, 1991
Haber et al. (Haber) 5,136,647 Aug. 4, 1992
Conner et al. (Conner) 5,579,393 Nov. 26, 1996
Claims 1-3, 5-9, 11-15 and 17-21 stand rejected under 35 U.S.C. § 103. As evidence of
obviousness, the examiner cites Fisher and Dyson with regard to claims 1 and 21, adding Haber
with regard to claims 2, 3, 5 and 6, and further adding Conner with regard to claims 7-9, 11-15
and 17-20.
Reference is made to the brief and answer for the respective positions of appellants and
the examiner.
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OPINION
With regard to the independent claim, the examiner provides Fisher as a general teaching
of a PACS system, but admits that Fisher does “not disclose either authenticating the images,
securing the transmission of the images through encryption, data compression, or image datasets
comprising an image header and image data” [answer-page 4]. The examiner then turns to
Dyson for a teaching of storing a pre-computed hash (the first identifier, at column 3, lines
36-42) locally on a computer, acknowledging the advantage of broadcasting a file from separate
storage locations across the communication network to many computers simultaneously, at
column 2, lines 46-56. The examiner then spends pages 5-7 of the answer, delineating the many
failures of Dyson and conjecturing on why so many of the missing claim limitations would have
been obvious to the artisan and how and why the combination of Fisher/Dyson would have
allowed for secured transmission through encryption and authentication of medical images in the
form of image datasets and would have provided certain benefits, without any specific evidence
to support those allegations.
Clearly, the examiner has not established a prima facie case of obviousness with regard to
the instant claimed subject matter.
While the following is not meant to be an exhaustive list of deficiencies in the examiner’s
case, it will suffice to show some of the errors in the examiner’s reasoning:
Claim 1 calls for an “image archive server” and recites how it is functionally intertwined
with other claimed elements. The examiner appears to agree that the applied references fail to
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show such an image archive server, contending merely that it would be “advantageous for the
pre-computed hashes to be stored in a central archive controlled by a server rather than each
computer [as taught by Dyson] having to store the pre-computed hashes separately because it
would not necessitate that each display computer devote it [sic] limited system resources to
storing hashes. It would have been obvious...to include a server controlling a storage device in
which pre-computed hashes would be placed and call that an authentication server” [answer-page
5]. The examiner has no reasonable basis for this conclusion as the applied references clearly do
not teach or suggest a central “archive server,” as claimed. The examiner has offered no
evidence that there would have been any advantage to storing pre-computed hashes in a central
archive controlled by a server and it would appear that the only evidence of this, on the record, is
appellants’ own disclosure.
While it is not clear what the examiner relies on for the teaching of the claimed
“acquisition computers” and the “display stations,” the examiner’s statement that a “single
computer could serve as both an acquisition and/or display computer” [answer-page 5-emphasis
added] falls far short of an evidentiary showing of obviousness since the mere fact that
something could be done does not, in and of itself, constitute obviousness within the meaning of
35 U.S.C. § 103.
While the examiner admits that Dyson does not teach the advantages of including an
identifier with the hash, the examiner concludes that it would have been obvious to include such
an identifier because, “without the identifier, it would be difficult to know which hash belongs to
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which data” [answer-page 6]. Again, the examiner makes an allegation but fails to point to
anything to support such an allegation. If Dyson disclosed a hash without an identifier, then,
clearly, all hashes must not need such an identifier. Accordingly, the examiner must show some
reason, suggested by the prior art, as to why the artisan would have been led to supply such
identifiers where none are taught.
Further, the examiner alleges that although Dyson fails to teach the advantages of
encrypting the pre-processed hashes and having the display computer decrypt the hash which was
received from the authentication server, it would have been obvious to include an encryption
module in the authentication server to encrypt hashes because Dyson equips each computer with
encryption/decryption modules. How can it possibly be obvious to encrypt hashes received from
an authentication server when there is no authentication server taught by the applied references?
The examiner’s rationale appears to be nothing more than a bevy of unsupported obviousness
conclusions based on previous, bootstrapped, unsupported conclusions of obviousness.
The examiner’s entire case is comprised of unsupported allegations of what would have
been “obvious” or “advantageous.” Even if certain things might have been well known, there
must still be some convincing reasoning as to what would have motivated the artisan to make the
proposed modifications. This factual question of motivation is material to patentability, and
cannot be resolved on subjective belief and unknown authority. It is improper, in determining
whether a person of ordinary skill would have been led to this combination of references, simply
to “[use] that which the inventor taught against its teacher.” In re Sang-Su Lee, 277 F.3d 1338,
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61 USPQ2d 1430 (Fed. Cir. 2002). When the examiner relies on what is asserted to be general
knowledge to negate patentability, that knowledge must be articulated and placed on the record.
We cannot rely on conclusory statements when dealing with particular combinations of prior art
and specific claims. In re Sang-Su Lee.
Even assuming, arguendo, that much of what the examiner alleges is true, there appears to
be no cogent rationale set forth as to why the artisan would have combined the PACS system
teachings of Fisher with Dyson which is concerned with verifying the integrity of a file stored
separately from a computer. There is nothing to suggest any use for Dyson’s storage of verifying
information in a centralized archive server.
Since neither Haber nor Conner provides for any of the deficiencies, as noted supra, in the
examiner’s case, the rejections based on these references in combination with Fisher and Dyson
must also fall.
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The examiner’s decision rejecting claims 1-3, 5-9, 11-15 and 17-21 under 35 U.S.C.
§ 103 is reversed.
REVERSED

James D. Thomas )
Administrative Patent Judge )
)
)
)
Errol A. Krass ) BOARD OF PATENT
Administrative Patent Judge ) APPEALS AND
) INTERFERENCES
)
)
Jerry Smith )
Administrative Patent Judge )

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C/O U.S. Philips Corp.
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