Ex parte Fischer

Board of Patent Appeals and Interferences

Feb 11, 2000

08464069 (B.P.A.I. Feb. 11, 2000)

Application for patent filed June 6, 1995, entitled1
"Method For Preventing Inadvertent Betrayal By A Trustee Of
Escrowed Digital Secrets," which is a continuation of
Application 08/130,126, filed October 4, 1993, now U.S. Patent
5,436,972, issued July 25, 1995.
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THIS OPINION WAS NOT WRITTEN FOR PUBLICATION
The opinion in support of the decision being entered
today (1) was not written for publication in a law
journal and (2) is not binding precedent of the Board.
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Paper No. 21
UNITED STATES PATENT AND TRADEMARK OFFICE

BEFORE THE BOARD OF PATENT APPEALS
AND INTERFERENCES

Ex parte ADDISON M. FISCHER

Appeal No. 1997-3178
Application 08/464,0691

HEARD: January 13, 2000

Before KRASS, BARRETT, and BARRY, Administrative Patent
Judges.
BARRETT, Administrative Patent Judge.
Appeal No. 1997-3178
Application 08/464,069
- 2 -
DECISION ON APPEAL
This is a decision on appeal under 35 U.S.C. § 134 from
the final rejection of claims 25, 26, and 29-46.
We affirm-in-part.
BACKGROUND
The disclosed invention involves the problem of
confirming the identity of a user who is seeking to recover
secret information, such as a lost password, using a
trustee. The trustee must have some way to positively
identify the user so that the secret information will not be
revealed to an imposter. A data structure holds both
standard information identifying the legitimate user,
encrypted private information which only the user knows and
which is used by the trustee to verify identity, and
encrypted secret information. The trustee decrypts the
encrypted portions of the data structure, uses the standard
and private information to verify the identity of the user,
and transmits the decrypted secret information (such as a
password) to the user.
Appeal No. 1997-3178
Application 08/464,069
We question whether the phrase "to recover the secret2
encrypted digital information" is correct. This suggests that
the trustee does nothing since the information is still
encrypted. Perhaps it was intended that the trustee recovers
"the secret digital information" as recited in claim 32.
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Claim 25 is reproduced below.2
25. A computer having a legitimate user of the
computer including a processor and a memory device
coupled to said processor, a digital data structure
corresponding to the legitimate user stored in said
memory device including:
identifying information identifying the legitimate
computer user, and
secret encrypted digital information other than
said identifying information,
wherein the digital data structure is used by a
trustee to confirm the identity of the legitimate
computer user and to recover the secret encrypted
digital information.
The Examiner relies on the following prior art:
Cole et al. (Cole) 5,091,939 February 25, 1992
Hardy et al. (Hardy) 5,222,135 June 22,
1993
Kaufman et al. (Kaufman) 5,418,854 May 23,
1995
(filed April 28,
1992)
Dziewit et al. (Dziewit) WO 92/09161 May
29, 1992
(International application published under the PCT)
Appeal No. 1997-3178
Application 08/464,069
Since claim 37 parallels rejected claim 30, it appears3
that the statement of the rejection should include claim 37.
Appellant has assumed that claim 37 is included in the
rejection.
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Claims 25, 26, and 29-46 stand rejected under 35 U.S.C.
§ 102(b) as being anticipated by Cole.
Claims 25, 26, 29, 30, 32, 33, 36, 37, 39, and 43-46
stand rejected under 35 U.S.C. § 102(b) as being anticipated
by Dziewit (WO 92/09161).
Claims 25, 26, 29, 30, 32, 33, 36, 39, and 43-46 stand
rejected under 35 U.S.C. § 102(e) as being anticipated by
Kaufman.3
Claims 25, 26, 29-33, 35-39, and 43-46 stand rejected
under 35 U.S.C. § 102(a) as being anticipated by Hardy.
We refer to the Final Rejection (Paper No. 7) (pages
referred to as "FR__") and the Examiner's Answer (Paper
No. 14) (pages referred to as "EA__") for a statement of the
Examiner's position and to the Appeal Brief (Paper No. 13)
(pages referred to as "Br__") and the Reply Brief (Paper
No. 16) (pages referred to as "RBr__") for a statement of
Appellant's arguments thereagainst.
OPINION
Appeal No. 1997-3178
Application 08/464,069
- 5 -
Claim interpretation
We begin by interpreting the claims.
First, the claims all recite a "digital data structure"
(emphasis added) which distinguishes over serial numbers,
warranty information, and other information that may be
printed on the computer or on paper in non-digital form and
somehow associated with the computer. See RBr2.
Second, claim 25 recites that the digital data
structure includes "identifying information identifying the
legitimate computer user" and claim 32 recites "storing
identifying information identifying the legitimate computer
user in an original digital data structure." Neither claim
requires that the identifying information is encrypted (for
example, with the manufacturer's (trustee's) public key) as
an encrypted escrow record. We interpret the "identifying
information" to correspond to the standard identifying
information in figure 2 which is optionally encrypted as
shown at 84 in figure 4. This interpretation is consistent
with claims 29 and 36, which enumerate the information shown
in figure 2, and with claims 30, 31, 37, and 38 which
correspond to the private identifying information and
Appeal No. 1997-3178
Application 08/464,069
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instructions at 86 in figure 4. Thus, claims 25 and 32
indicate that the identifying information is not encrypted
and do not define over the use of non-encrypted data as
identifying information. Claims 25 and 32 do not cover the
disclosed concept of using encrypted information to confirm
the identity of the legitimate user, i.e., an imposter could
substitute his own identifying information because it is not
encrypted. Similarly, claims 30, 31, 37, and 38 do not
require encrypting private information.
Third, claim 25 is directed to a digital data structure
stored in a memory. Claim 25 includes a "wherein" clause
which expresses that the digital data structure is used by a
trustee to confirm the identity of the legitimate computer
user and to recover the secret encrypted digital
information. We agree with the Examiner's position (argued
by Appellant at Br18-19) that the "wherein" clause is merely
a statement of intended use of the data structure claim
(although we do not find where this position is stated in
the rejection), which limitation is met as long as the data
structure is capable of such use. We are not persuaded by
Appellant's argument (Br19) that the language in the
Appeal No. 1997-3178
Application 08/464,069
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"wherein" clause is functional language which must be shown
in a reference. Claim 25 is directed to the digital data
structure, not a system which uses the digital data
structure, and the "wherein" clause does not positively
recite any structural limitation to the digital data
structure. Method claim 32, by comparison, recites a method
step using the digital data structure which is a limitation
on the method.
Fourth, claims 25 and 32 recite "secret encrypted
digital information other than said identifying
information," which is not limited to the secret information
being a password. The secret information could be anything.
Appellant's arguments that references such as Dziewit and
Kaufman do not recognize the lost password problem (e.g.,
Br12, Br18) are not commensurate in scope with the broad
claim language.
Fifth, claim 25 recites "wherein the digital data
structure is used by a trustee to confirm the identity of
the legitimate computer user and to recover the secret
encrypted digital information" and claim 32 recites "the
trustee using said digital data structure to confirm the
Appeal No. 1997-3178
Application 08/464,069
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identity of the legitimate computer user, and after positive
confirmation of identity, recovering the secret digital
information." Claim 25 recites recovering "secret encrypted
digital information" instead of recovering "secret digital
information" as recited in claim 32. In claims 25 and 32,
the trustee uses the "digital data structure" to confirm the
user identity, not just the "identifying information"
portion of the "digital data structure"; thus, the trustee
could use all or part of the digital data structure.
Furthermore, claims 25 and 32 do not recite how the trustee
recovers the secret (encrypted) digital information from the
digital data structure; the secret digital information could
be encrypted with a public key (as in Kaufman) and the
trustee could just apply its private key (as in Kaufman) to
decrypt and recover the information.
Anticipation
"Anticipation is established only when a single prior
art reference discloses, expressly or under principles of
inherence, each and every element of a claimed invention."
RCA Corp. v. Applied Digital Data Systems, Inc.,
730 F.2d. 1440, 1444, 221 USPO 385, 388 (Fed. Cir. 1984).
Appeal No. 1997-3178
Application 08/464,069
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Cole
Cole stores encrypted primary and secondary passwords.
The user enters his password, which is then encrypted and
compared to the stored encrypted primary password. The
computer boots if there is a match. If the user forgets his
password, he may call the computer manufacturer to obtain a
valid alternate (secondary) password (col. 5, lines 45-49).
Alternatively, the secondary password may be generated from
external information instead of being stored.
The Examiner states (FR2-3): "The means for storing
identifying information identifying the computer user
features of claim 25 reads on the storage of the primary
password in Cole. The storing of the secret digital
information in encrypted format features of claim 25 reads
on the storage of the primary password in encrypted format
of the last line of the abstract."
Appellant argues (Br7): "Cole's primary password
(encrypted or otherwise) cannot be both the claimed
identifying information and the secret digital information."
We agree with Appellant. Furthermore, we note that
Cole does not store the password in decrypted form because
Appeal No. 1997-3178
Application 08/464,069
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this would compromise security. Moreover, we do not see how
a password can be considered information identifying a user.
Appellant argues (Br6-7): "Cole fails to disclose the
claimed digital data structure corresponding to a legitimate
user that stores 'identifying information identifying the
legitimate computer user' as well as 'secret digital
information in an encrypted form other than said identifying
information.'"
The Examiner finds the digital data structure
limitations in "Cole at col. 2, lines 8-11 and col. 6,
lines 18 [sic, 1-8]" (EA5) and "with Cole an alternate
password is provided" (EA5). Thus, the Examiner considers
the secondary (alternate) password to correspond to the
"secret encrypted digital information." Cole, column 2,
lines 8-11, states: "Upon verification of the user's
identity, the manufacturer or authorized agent supplies an
alternate password to the user." Cole, column 6, lines 1-8,
states: "Before issuing the alternate password, the
computer manufacturer verifies the identity of the user,
e.g. via warranty information or from a list of computer
serial numbers and associated owners/users. In this
Appeal No. 1997-3178
Application 08/464,069
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embodiment of the invention, when the caller has adequately
identified himself, the computer manufacturer instructs the
user to read the date displayed on the screen."
The stored encrypted secondary password in Cole
corresponds to "secret encrypted digital information." We
do not agree with Appellant's argument, with respect to
similar language in claim 32, that "Cole fails to disclose
storing 'secret encrypted digital information other than
said identifying information in said digital data
structure'" (Br8) because we rely on the embodiment where
the secondary password is stored, not the embodiment
referred to by Appellant where the secondary password is
generated from data external to the computer such as the
date. The issue is whether Cole discloses a digital data
structure including "identifying information identifying the
legitimate computer user."
The portions of Cole pointed out by the Examiner do not
state that the identifying information was stored in digital
form along with the encrypted secondary password in a data
structure. The quote from column 2 does not state what
information is used to confirm the identity of the user or
Appeal No. 1997-3178
Application 08/464,069
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where the information is stored. The quote from column 6
indicates that external printed (i.e., non-digital)
information is used by the manufacturer to confirm the
identity of the user. Column 6 refers to an embodiment
where a secondary password is generated, not stored,
although the identification procedure could be the same. We
agree with Appellant that the Examiner has not identified a
digital data structure in Cole including "identifying
information identifying the legitimate computer user" and we
do not find any such teaching in Cole. The anticipation
rejection of claims 25, 26, 29-31, and 39-42 over Cole is
reversed.
The arguments with respect to method claim 32 are
similar to claim 25. The rejection of claims 32-38, and
44-46 are reversed for the reasons stated in connection with
claim 25.
Dziewit (WO 92/09161)
The Examiner states that the limitations of the digital
data structure are found in "Dziewit at page 30, 'Third
Party Trustee'" (EA5) and "with Dziewit secret encrypted
information such as an encrypted contract is provided"
Appeal No. 1997-3178
Application 08/464,069
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(EA5). The Examiner also relies on the last two lines on
page 29 (FR3).
The cited portion of Dziewit on page 30 is concerned
with using a third party trustee in the process of
authenticating electronically-documented contract
transactions. Page 29 of Dziewit discloses that
transmissions may be encrypted.
Appellant's argument with respect to claim 25 that
Dziewit fails to disclose use of information by a trustee to
confirm the identity of the legitimate computer user and to
recover the secret encrypted digital information is not
persuasive. Claim 25 is directed to a digital data
structure stored in a computer memory, not to a system
having a trustee which uses the contents of the digital data
structure. As discussed in the "Claim interpretation"
section, the "wherein" clause is considered a statement of
intended use.
Appellant argues (Br12): "The Examiner identifies no
specific digital data structure in Dziewit that includes
both types of claimed information. An encrypted, digitally
signed copy of the electronic contract file stored on disk
Appeal No. 1997-3178
Application 08/464,069
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is not the same thing as the claimed data structure in
claim 25 which includes information identifying a legitimate
computer user along with secret digital information in
encrypted form other than that identifying information."
We do not understand what the Examiner considers to be
the claimed digital data structure. It is true that Dziewit
discloses transmitting a contract to the parties using
encryption (page 29). The encryption provides security
during transmission but is not intended to keep the contract
secret from the parties at either end. Thus, the
transmitted encrypted contract cannot be considered to be
"secret encrypted digital information." However, assuming
the encrypted contract is the "secret encrypted digital
information," the Examiner does not explain what constitutes
the "identifying information identifying the legitimate
computer user." Because we find that Dziewit fails to
disclose "identifying information identifying the legitimate
computer user" and "secret encrypted digital information" in
a "digital data structure," the anticipation rejection of
claims 25, 26, 29, 30, 39, and 43 over Dziewit is reversed.
Appeal No. 1997-3178
Application 08/464,069
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The arguments with respect to method claim 32 are
similar to claim 25. In addition, claim 32 recites "the
trustee using said digital data structure to confirm the
identity of the legitimate computer user, and after positive
confirmation of identity, recovering the secret digital
information." We do not find these limitations in Dziewit
even giving the limitations a very broad interpretation.
The trustee in Dziewit is merely a third person used for
security reasons and the Examiner does not explain how the
trustee acts to confirm a legitimate computer user. The
rejection of claims 32, 33, 36, 37, and 44-46 is reversed
for the reasons stated in connection with claim 25 and
because Dziewit does not teach the steps performed by the
trustee.
Kaufman
The Examiner states that the limitations of the digital
data structure are found in "Kaufman at col. 6, lines 41-49"
(EA5) and "with Kaufman public key certificates and
encrypted 'long term' credentials are provided" (EA5).
Kaufman, column 6, lines 41-49 states:
Appeal No. 1997-3178
Application 08/464,069
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In an alternate embodiment of the authentication
arrangement, the CSS 24 and the LA 26 may be combined
into a single entity. Yet, in accordance with the
exemplary embodiment of the invention described below,
the CSS and LA are separate nodes. The CSS 24 is
accessed at registration to store a user's long-term
credential in a database directory and is thereafter
accessed at login by the workstation 12 to retrieve
that credential for authentication purposes, as
described below.
This portion of Kaufman is not very helpful in
explaining how the claim limitations are met and we do not
understand why the Examiner relies on the embodiment where
the CSS and the LA are combined. Nevertheless, we find that
Kaufman anticipates claims 25, 29, and 32, and 36.
The CSS (certificate storage server) node 24 shown in
figure 3 holds a "digital data structure" including the
"username" N, which we find corresponds to the claimed
"identifying information identifying the legitimate computer
user" in claims 25 and 32. The data structure in CSS 24
also includes a doubly encrypted "credential" {{U} , H2}H1 LA-PUB
which contains an encrypted private key U (col. 4,
lines 26-32). For purposes of discussion, we take the
encrypted quantity {U} to be the claimed "secret digitalH1
information." {U} is concatenated with hash total H2 andH1
encrypted with the public key of the login agent (LA),
Appeal No. 1997-3178
Application 08/464,069
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LA-PUB, to form {{U} , H2} , which corresponds to theH1 LA-PUB
claimed "secret encrypted digital information other than
said identifying information" stored in the "digital data
structure." The CSS 24 is "coupled to said processor" of
the legitimate user, i.e., to workstation 12. Although the
"wherein" clause of claim 25 is a mere statement of intended
use, the LA node 26 acts as a "trustee" and "the digital
data structure is used by a trustee to confirm the identity
of the legitimate computer user and to recover the secret
encrypted digital information." That is, LA 26 recovers the
secret digital information {U} by decrypting using theH1
private key LA-PRIV as shown in figure 5 and stripping H2.
The user identity is confirmed for a given user name N if
the hash total H2 from the decrypted credential {U} , H2H1
associated with the name N matches the hash total H2A
received from the workstation (col. 8, lines 11-24).
Remember that claim 25 states that the digital data
structure is used to confirm the identity, not just the
identifying information portion of the data structure.
Claim 25 is open ended does not exclude the numerous
additional and complicated steps in Kaufman. Neither
Appeal No. 1997-3178
Application 08/464,069
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claim 25 nor claim 32 recites doing anything with the
recovered secret digital information, such as actually
sending it to the user; however, the LA in Kaufman encrypts
{U} with key K and send it to the user who can recover U. H1
The method of claim 32 is anticipated for the same reasons
as claim 25. The "name" N in Kaufman is one of the
enumerated pieces of identifying information recited in
claims 29 and 36. The anticipation rejection of claims 25,
29, 32, and 36 over Kaufman is sustained.
Appellant argues (Br18): "In general, there is no
recognition in Kaufman that a legitimate user may have
forgotten his password. Nor is there any provision in
Kaufman to permit a legitimate user to obtain that password
from a trustee." However, claims 25 and 32 are not limited
to the lost password problem. The "secret digital
information" can be the encrypted quantity {U} , theH1
encrypted private key U, in Kaufman. The "secret encrypted
digital information" is {{U} , H2} . Thus, the argumentH1 LA-PUB
is not persuasive.
Appellant argues (Br18): "Kaufman fails to disclose a
trustee. Nor does Kaufman disclose a trustee that uses the
Appeal No. 1997-3178
Application 08/464,069
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information stored in the claimed digital data structure to
both 'confirm the identity of the legitimate computer user
and to recover the secret digital information.' The log-in
agent is not a 'trustee.'" Appellant argues that the login
agent (LA) is not trusted with the user's private key and,
as a result, the LA cannot impersonate a legitimate user.
Appellant evidently reads a lot into the term
"trustee," but does not state exactly what. Since the LA is
disclosed to be "semi-trusted" (col. 4, line 11), we find
this to meet the "trustee" limitation absent any
qualifications on the term in the claim. There can be many
levels of "trustee." Claims 25 and 32 do not require the
"secret digital information" to be understandable by the
trustee. The argument is not persuasive.
With respect to claims 26 and 33, the Examiner states
"that the LA identifier includes the public key LA-PUB"
(EA7). The LA is not information identifying the trustee
stored in the digital data structure in figure 4 of Kaufman.
The anticipation rejection of claims 26 and 33, and
dependent claims 43 and 44, over Kaufman is reversed.
Appeal No. 1997-3178
Application 08/464,069
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With respect to claims 30 and 37, the Examiner refers
to column 8, lines 8-24. We do not find anything in the
cited portion of Kaufman, or in the rest of Kaufman, that
constitutes instructions originated by the legitimate
computer user to be followed by the trustee in the event an
applicant seeks to gain access to secret information in the
digital data structure in figure 4 of Kaufman. The
anticipation rejection of claims 30 and 37 over Kaufman is
reversed.
With respect to claim 39, the Examiner refers to the
user's private key at column 8, line 28 (EA7). However, we
do not find any question authored by the legitimate computer
user to be posed by the trustee attempting to recover a
password or encryption key in the digital data structure in
figure 4 of Kaufman and the Examiner does not point to
anything that would meet this limitation. The anticipation
rejection of claim 39 over Kaufman is reversed.
With respect to claim 45, the Examiner points to
column 8, lines 20-25 (EA8). We do not find the steps of
obtaining and comparing credentials, as claimed, at that
location or elsewhere in Kaufman. The anticipation
Appeal No. 1997-3178
Application 08/464,069
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rejection of claim 45 and dependent claim 46 over Kaufman is
reversed.
Hardy
The Examiner states that the limitations of the digital
data structure are found in "Hardy at col. 2, lines 34-44"
(EA5) and "with Hardy coded release data is provided" (EA5).
Appellant argues that Hardy does not disclose storing
information identifying the legitimate computer user (Br21):
"Hardy's display screen 30 does not include information that
identifies the legitimate computer user. Rather, the
displayed information relates to the computer itself, i.e.,
the computer's serial number, and a random code that does
not depend 'on any other parameter which can be controlled
by the user.' Column 5, lines 3-4."
We do not find where the Examiner addresses this
argument. The random code 32 and the serial number 33 of
the workstation involved which are communicated to the
authorized service S do not identify the user. Accordingly,
the anticipation rejection of claims 25, 26, 29-33, 35-39,
and 43-46 over Hardy is reversed.
CONCLUSION
Appeal No. 1997-3178
Application 08/464,069
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The rejection of claims 25, 26, and 29-46 over Cole is
reversed.
The rejection of claims 25, 26, 29, 30, 32, 33, 36, 37,
39, and 43-46 over Dziewit is reversed.
The rejection of claims 25, 29, 32, and 36 over Kaufman
is sustained. The rejection of claims 26, 30, 33, 37, 39,
and 43-46 over Kaufman is reversed.
The rejection of claims 25, 26, 29-33, 35-39, and 43-46
over Hardy is reversed.
Appeal No. 1997-3178
Application 08/464,069
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No time period for taking any subsequent action in
connection with this appeal may be extended under 37 CFR
§ 1.136(a).
AFFIRMED-IN-PART
ERROL A. KRASS )
Administrative Patent Judge )
)
)
)
) BOARD OF
PATENT
LEE E. BARRETT ) APPEALS
Administrative Patent Judge ) AND
) INTERFERENCES
)
)
)
LANCE LEONARD BARRY )
Administrative Patent Judge )
Appeal No. 1997-3178
Application 08/464,069
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NIXON & VANDERHYE
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