Prosecution Insights
Last updated: April 19, 2026
Application No. 17/310,016

PROBABILISTIC SHARED SECRET VALIDATION

Final Rejection §103
Filed
Jul 09, 2021
Examiner
NARRAMORE, BLAKE I
Art Unit
2438
Tech Center
2400 — Computer Networks
Assignee
British Telecommunications Public Limited Company
OA Round
6 (Final)
78%
Grant Probability
Favorable
7-8
OA Rounds
2y 8m
To Grant
99%
With Interview

Examiner Intelligence

Grants 78% — above average
78%
Career Allow Rate
126 granted / 161 resolved
+20.3% vs TC avg
Strong +25% interview lift
Without
With
+24.8%
Interview Lift
resolved cases with interview
Typical timeline
2y 8m
Avg Prosecution
26 currently pending
Career history
187
Total Applications
across all art units

Statute-Specific Performance

§101
8.3%
-31.7% vs TC avg
§103
56.2%
+16.2% vs TC avg
§102
10.2%
-29.8% vs TC avg
§112
20.6%
-19.4% vs TC avg
Black line = Tech Center average estimate • Based on career data from 161 resolved cases

Office Action

§103
Detailed Action This is a Final Office action in response to communications received on 6/27/2025. Claims 1, 5 and 6 were amended. Claim 7 was canceled. Claim 3 was previously canceled. Claims 1-2, 4-6 and 8-11 are pending and are examined. Notice of Pre-AIA or AIA Status The present application, filed on or after March 16, 2013, is being examined under the first inventor to file provisions of the AIA . Response to Arguments Applicant's arguments regarding the rejection under 35 U.S.C. 103 of the claims under Yao, Wood and Dwarkha have been considered, and are found unpersuasive. Applicant argues on pages 5-6 of the Remarks, filed 6/27/2025, the cited prior art fail to teach or suggest “transferring association of the digital asset from the incumbent telephony service provider entity to the requesting telephony service provider entity, wherein the digital asset is a telephone number and the association of the telephone number with an entity corresponding to a telephony service provider permits provision of telephony services by the telephony service provider using the telephone number” because “There is no teaching here, however, that the association of the telephone number with an entity corresponding to a telephony service provider permits provision of telephony services by the telephony service provider using the telephone number." However, Examiner respectfully disagrees. Dwarkha at [0006] expressly teaches that when a customer retains a phone number while switching from a first to a second provider, a third telephony provider “needs to direct the call to the second telephony service provider.” This directly corresponds to associating the telephone number with the new provider and permitting provision of telephony services using that number. Applicant’s distinction between “assignment” and “permitting provision” is semantic. The act of assignment in Dwarkha inherently permits the provision of services by the new provider, because without the reassignment or association, calls could not be directed to the new provider. Thus Dwarkha teaches or at least suggests the claimed feature. Applicant additionally argues that “It also would not have been obvious to modify Yao and Wood as suggested. The Office Action itself asserts that there are at least two different fields of endeavor, depending upon which references it is attempting to justify combining:" secure exchange of information in a blockchain system" (p. 7, for combining Yao and Wood; and p. 10, for combining Yao, Wood, and Ortiz); and "management of transaction data" (p. 13, for combining Yao, Wood, and Dwarkha). The Office must contort itself here because Dwarkha never mentions "secure exchange of information," much 6 less via blockchain.” However, Examiner respectfully disagrees. Examiner notes that the mentioned references are all directed to systems for the management and transfer of digital assets or transaction data between entities. Yao and Wood are directed to secure exchange of digital assets using blockchain based systems. Dwarkha is directed to the reassignment of telephone numbers, which constitutes the transfer of digital identifiers. While the references may emphasize different implementations, they nonetheless fall under the broader shared field of endeavor: transactional management (i.e., not “different” fields of endeavor, rather a broader shared field of endeavor). Consequently, the rejection of the claims under 35 U.S.C. 103 is sustained. Claim Rejections - 35 USC § 103 In the event the determination of the status of the application as subject to AIA 35 U.S.C. 102 and 103 (or as subject to pre-AIA 35 U.S.C. 102 and 103) is incorrect, any correction of the statutory basis (i.e., changing from AIA to pre-AIA ) for the rejection will not be considered a new ground of rejection if the prior art relied upon, and the rationale supporting the rejection, would be the same under either status. The following is a quotation of 35 U.S.C. 103 which forms the basis for all obviousness rejections set forth in this Office action: A patent for a claimed invention may not be obtained, notwithstanding that the claimed invention is not identically disclosed as set forth in section 102, if the differences between the claimed invention and the prior art are such that the claimed invention as a whole would have been obvious before the effective filing date of the claimed invention to a person having ordinary skill in the art to which the claimed invention pertains. Patentability shall not be negated by the manner in which the invention was made. Claims 1-2, 4 and 8-11 are rejected under 35 U.S.C. 103 as being unpatentable over Yao (NPL “A Novel Blockchain-Based Authentication Key Exchange Protocol and Its Applications”, hereinafter referred to as Yao), in view of Wood (US 20190361842 A1). Regarding claim 1, Yao teaches the limitations of claim 1 substantially as follows: A computer implemented method of shared secret validation for a transaction to transfer an association of a digital asset represented in a distributed transactional database from an incumbent [telephony] service provider entity to a requesting [telephony] service provider entity, (Yao; Page 611, right column, “Step 1” and “Step 2”: Initializing a Bloom filter and sending to other peers to determine if a shared secret exists among peers (i.e. shared secret validation), if a key exchange is performed, a transaction is constructed which points to the recipient (i.e. to transfer an association of a digital asset represented in a distributed transactional database from an incumbent service provider entity to a requesting service provider entity)) the association of the digital asset with the incumbent [telephony] service provider being indicated in at least one transaction in the distributed transactional database, (Yao; Page 611, right column, “Step 1” and “Step 2”: Hashing the tags received to construct a transaction as part of key exchange procedure (i.e. association of the digital asset with the incumbent service provider being indicated in at least one transaction in the distributed transactional database)) the digital asset having associated a probabilistic data structure encoding at least one digital hash of each of a plurality of secrets including the shared secret, and (Yao; Page 610, left column, “B. Bloom Filter”; Page 611, right column, “Step 1”: Initializing a Bloom filter for sending to other peers by selecting some well-known keywords (i.e. the digital asset having associated a probabilistic data structure encoding at least one digital hash of each of a plurality of secrets including the shared secret)) the transaction to transfer the association of the digital asset including a hash of the shared secret, the method comprising: (Yao; Page 611, right column, “Step 1” and “Step 2”: Hashing the tags received to construct a transaction as part of key exchange procedure (i.e. the transaction to transfer the association of the digital asset including a hash of the shared secret)) responsive to the determining being positive, validating the transaction to transfer the association of the digital asset; (Yao; Page 611, right column, “Step 1” and “Step 2”: Initializing a Bloom filter to determine if a secret is shared amongst peers and based on this a transaction is constructed which points to the recipient (i.e. responsive to the determining being positive, validating the transaction to transfer the association of the digital asset)) responsive to the validating, committing the transaction to transfer the association of the digital asset in the database; and transferring association of the digital asset from the incumbent [telephony] service provider entity to the requesting [telephony] service provider entity, (Yao; Page 611, right column, “Step 1” and “Step 2”: if a key exchange is performed, a transaction is constructed which points to the recipient (i.e. committing the transaction to transfer the association of the digital asset in the database; and transferring association of the digital asset to the requesting service provider entity)) Yao does not teach the limitations of claim 1 as follows: determining, with at least a predetermined degree of certainty, whether the hash of the shared secret in the transaction to transfer the association of the digital asset corresponds to the digital hash of the shared secret in the probabilistic data structure; incumbent telephony service provider entity requesting telephony service provider entity wherein the digital asset is a telephone number and the association of the telephone number with an entity corresponding to a telephony service provider permitting the provision of telephony services by the telephony service provider using the telephone number. However, in the same field of endeavor, Wood discloses the limitations of claim 1 as follows: determining, with at least a predetermined degree of certainty, whether the hash of the shared secret in the transaction to transfer the association of the digital asset corresponds to the digital hash of the shared secret in the probabilistic data structure; (Wood; Para. [0054]: The Bloom filter is probabilistic and is designed to return a true negative answer with 100% probability, however there is a slight probability of false positive. Due to this probability, if there is a query match then an additional verification step is necessary to confirm that the element is truly in the set (i.e. determining, with at least a predetermined degree of certainty, whether the hash of the shared secret in the transaction to transfer the association of the digital asset corresponds to the digital hash of the shared secret in the probabilistic data structure)) Wood is combinable with Yao because all are from the same field of endeavor of secure exchange of information in a blockchain system. Therefore, it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to have modified system of Yao to incorporate a predetermined probability threshold for the bloom filter as in Wood in order to improve the security of the system by providing a predetermined threshold of confidence which a match must meet. Yao and Wood do not teach the limitations of claim 1 as follows: incumbent telephony service provider entity requesting telephony service provider entity wherein the digital asset is a telephone number and the association of the telephone number with an entity corresponding to a telephony service provider permitting the provision of telephony services by the telephony service provider using the telephone number. However, in the same field of endeavor, Dwarkha discloses the limitations of claim 1 as follows: incumbent telephony service provider entity (Dwarkha; Para. [0006]: Assigning a telephone number from one telephony service provider (i.e. incumbent) to a second) requesting telephony service provider entity (Dwarkha; Para. [0006]: Assigning a telephone number from one telephony service provider to a second (i.e. requesting)) wherein the digital asset is a telephone number and (Dwarkha; Para. [0006]: Assigning a telephone number from one telephony service provider to a second (i.e. the digital asset is a telephone number)) the association of the telephone number with an entity corresponding to a telephony service provider permitting the provision of telephony services by the telephony service provider using the telephone number. (Dwarkha; Para. [0006]: Assigning a telephone number from one telephony service provider to a second (i.e. the association of the telephone number with an entity corresponding to a telephony service provider permitting the provision of telephony services by the telephony service provider using the telephone number)) Dwarkha is combinable with Yao and Wood because all are from the same field of endeavor of management of transaction data. Therefore, it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to have modified system of Yao and Wood to incorporate transactional assignment of telephone numbers to telephony services as in Dwarkha in order to expand the functionality of the system by providing a means by which transacted digital assets may also include phone numbers. Regarding claim 2, Yao, Wood and Dwarkha teach the limitations of claim 1. Yao, Wood and Dwarkha teach the limitations of claim 2 as follows: The method of claim 1, wherein the probabilistic data structure is a Bloom filter. (Yao; Page 611, right column, “Step 1”: Initializing a Bloom filter) Regarding claim 4, Yao, Wood and Dwarkha teach the limitations of claim 1. Yao, Wood and Dwarkha teach the limitations of claim 4 as follows: The method of claim 1, further comprising, in response to the determining being negative, rejecting the transaction. (Yao; Page 611, right column, “Step 1” to Page 612, left column, “Step 4”: If at any of the steps validation fails, the protocol involving the hash based key exchange is aborted (i.e. in response to the determining being negative, rejecting the transaction)) Regarding claim 8, Yao, Wood and Dwarkha teach the limitations of claim 1. Yao, Wood and Dwarkha teach the limitations of claim 8 as follows: The method of claim 1, wherein the plurality of secrets includes one or more of: personal information; private information; an address indication; a geographic location; a postal code; a password; and a key. (Yao; Page 610, left column, “B. Bloom Filter”; Page 611, right column, “Step 1”: Initializing a Bloom filter for sending to other peers by selecting some well-known keywords (i.e. the plurality of secrets includes one or more of: personal information; private information; an address indication; a geographic location; a postal code; a password; and a key)) Regarding claim 9, Yao, Wood and Dwarkha teach the limitations of claim 1. Yao, Wood and Dwarkha teach the limitations of claim 9 as follows: The method of claim 1, wherein the distributed transactional database is a blockchain. (Yao; Abstract: Blockchain based exchange protocol (i.e. wherein the distributed transactional database is a blockchain)) Regarding claim 10, Yao, Wood and Dwarkha teach the limitations of claim 1. Yao, Wood and Dwarkha teach the limitations of claim 10 as follows: A computer system including a processor and memory storing computer program code for performing the method of claim 1. (Yao; Abstract; Page 610, “A. Blockchain”: Blockchain based exchange protocol populated by ledger member nodes for performing the function of the system) Regarding claim 11, Yao, Wood and Dwarkha teach the limitations of claim 1. Yao, Wood and Dwarkha teach the limitations of claim 11 as follows: A non-transitory computer-readable storage medium comprising computer program code to, when loaded into a computer system and executed thereon, cause the computer to perform the method as claimed in claim 1. (Yao; Abstract; Page 610, “A. Blockchain”: Blockchain based exchange protocol populated by ledger member nodes for performing the function of the system) Claims 5 and 6 are rejected under 35 U.S.C. 103 as being unpatentable over Yao (NPL), in view of Wood (US 20190361842 A1), further in view of Dwarkha (US 2014/0313941 A1), as applied to claim 1, further in view of Ortiz (US 2018/0268401 A1). Regarding claim 5, Yao, Wood and Dwarkha teach the limitations of claim 1. Yao, Wood and Dwarkha teach the limitations of claim 5 as follows: The method of claim 1, further comprising receiving an indication from the incumbent [telephony] service provider entity that the hash in the transaction to transfer the association of the digital asset is invalid and (Yao; Page 611, right column, “Step 1” to Page 612, left column, “Step 4”: If at any of the steps validation fails, the protocol involving the hash based key exchange is aborted (i.e. receiving an indication from the incumbent entity that the hash in the transaction to transfer the association of the digital asset is invalid)) incumbent telephony service provider entity (Dwarkha; Para. [0006]: Assigning a telephone number from one telephony service provider (i.e. incumbent) to a second) Yao, Wood and Dwarkha do not teach the limitations of claim 5 as follows: committing a second transaction to the database to reverse the transfer of association of the digital asset such that the digital asset is re-associated with the incumbent [telephony] service provider entity. However, in the same field of endeavor, Ortiz discloses the limitations of claim 5 as follows: committing a second transaction to the database to reverse the transfer of association of the digital asset such that the digital asset is re-associated with the incumbent [telephony] service provider entity. (Ortiz; Paras. [0138] & [0140]: A user-side request for a reverse transaction in a blockchain transaction platform (i.e. committing a second transaction to the database to reverse the transfer of association of the digital asset such that the digital asset is re-associated with the incumbent entity)) Ortiz is combinable with Yao, Wood and Dwarkha because all are from the same field of endeavor of management of transaction data. Therefore, it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to have modified system of Yao, Wood and Dwarkha to incorporate the ability to perform transactions and issue reversals of transactions as in Ortiz in order to improve the security of the system by providing a means by which transactions, returns or reversals of transactions may also be performed in a secure blockchain system. Regarding claim 6, Yao, Wood and Dwarkha teach the limitations of claim 1. Yao, Wood and Dwarkha teach the limitations of claim 6 as follows: telephony services (Dwarkha; Para. [0006]: Assigning a telephone number from one telephony service provider to a second (i.e. telephony services)) incumbent telephony service provider entity (Dwarkha; Para. [0006]: Assigning a telephone number from one telephony service provider (i.e. incumbent) to a second) requesting telephony service provider entity (Dwarkha; Para. [0006]: Assigning a telephone number from one telephony service provider to a second (i.e. requesting)) association of an entity corresponding to a telephony service provider entity (Dwarkha; Para. [0006]: Assigning a telephone number from one telephony service provider to a second (i.e. telephony service provider entity)) Yao, Wood and Dwarkha do not teach the limitations of claim 6 as follows: The method of claim 1, wherein the digital asset is an identifier of a resource used in the provision of the [telephony] services, the [telephony] services being providable separately by the incumbent [telephony] service provider entity and the requesting [telephony] service provider entity, and association of an entity corresponding to a [telephony] service provider entity with the digital asset permits provision of the [telephony] services using the resource by the [telephony] service provider entity. However, in the same field of endeavor, Ortiz discloses the limitations of claim 6 as follows: The method of claim 1, wherein the digital asset is an identifier of a resource used in the provision of the [telephony] services, (Ortiz; Para. [0138]: Redeeming loyalty points for rewards (i.e. the digital asset is an identifier of a resource used in the provision of a service)) the [telephony] services being providable separately by the incumbent [telephony] service provider entity and the requesting [telephony] service provider entity, and (Ortiz; Para. [0138]: Redeeming loyalty points associated with a customer account for rewards (i.e. the service being providable separately by the incumbent service provider entity and the requesting service provider entity)) association of an entity corresponding to a [telephony] service provider entity with the digital asset permits provision of the [telephony] services using the resource by the [telephony] service provider entity. (Ortiz; Paras. [0138] & [0144]: Redeeming loyalty points associated with a customer account for rewards from a merchant with a loyalty platform (i.e. association of an entity corresponding to a service provider entity with the digital asset permits provision of the service using the resource by the service provider entity)) Ortiz is combinable with Yao, Wood and Dwarkha because all are from the same field of endeavor of management of transaction data. Therefore, it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to have modified system of Yao, Wood and Dwarkha to incorporate the ability to perform transactions and issue reversals of transactions as in Ortiz in order to improve the security of the system by providing a means by which varying transactions, such as returns or reversals of transactions may also be securely performed in a blockchain system. Prior Art Considered But Not Relied Upon Cantrell (US 2019/0303935 A1) which teaches a method for preventing invalid reverse transactions in a distributed environment is provided in which a first block is added to a first cryptographically verifiable ledger containing a transaction identifier and an executable program for preventing a reversal of a transaction. Li (US 2019/0097790 A1) which teaches a method for establishing consensus between a plurality of distributed nodes connected via a data communication network includes preparing a set of random numbers, wherein each of the random numbers is a share of an initial secret, wherein each share of the initial secret corresponds to one of a plurality of active nodes. Conclusion For the above-stated reasons, claims 1-2, 4-6 and 8-11 are rejected. THIS ACTION IS MADE FINAL. Applicant is reminded of the extension of time policy as set forth in 37 CFR 1.136(a). A shortened statutory period for reply to this final action is set to expire THREE MONTHS from the mailing date of this action. In the event a first reply is filed within TWO MONTHS of the mailing date of this final action and the advisory action is not mailed until after the end of the THREE-MONTH shortened statutory period, then the shortened statutory period will expire on the date the advisory action is mailed, and any extension fee pursuant to 37 CFR 1.136(a) will be calculated from the mailing date of the advisory action. In no event, however, will the statutory period for reply expire later than SIX MONTHS from the mailing date of this final action. Any inquiry concerning this communication or earlier communications from the examiner should be directed to BLAKE ISAAC NARRAMORE whose telephone number is (303)297-4357. The examiner can normally be reached on Monday - Friday 0700-1700 MT. Examiner interviews are available via telephone, in-person, and video conferencing using a USPTO supplied web-based collaboration tool. To schedule an interview, applicant is encouraged to use the USPTO Automated Interview Request (AIR) at http://www.uspto.gov/interviewpractice. If attempts to reach the examiner by telephone are unsuccessful, the examiner’s supervisor, Taghi T Arani can be reached on (571) 272-3787. The fax phone number for the organization where this application or proceeding is assigned is 571-273-8300. Information regarding the status of an application may be obtained from the Patent Application Information Retrieval (PAIR) system. Status information for published applications may be obtained from either Private PAIR or Public PAIR. Status information for unpublished applications is available through Private PAIR only. For more information about the PAIR system, see https://ppair-my.uspto.gov/pair/PrivatePair. Should you have questions on access to the Private PAIR system, contact the Electronic Business Center (EBC) at 866-217-9197 (toll-free). If you would like assistance from a USPTO Customer Service Representative or access to the automated information system, call 800-786-9199 (IN USA OR CANADA) or 571-272-1000. /B.I.N./Examiner, Art Unit 2438 /TAGHI T ARANI/Supervisory Patent Examiner, Art Unit 2438
Read full office action

Prosecution Timeline

Jul 09, 2021
Application Filed
May 17, 2023
Non-Final Rejection — §103
Aug 23, 2023
Response Filed
Dec 02, 2023
Final Rejection — §103
Feb 08, 2024
Response after Non-Final Action
Mar 08, 2024
Request for Continued Examination
Mar 16, 2024
Response after Non-Final Action
Jul 03, 2024
Non-Final Rejection — §103
Sep 11, 2024
Response Filed
Sep 16, 2024
Final Rejection — §103
Dec 03, 2024
Response after Non-Final Action
Jan 10, 2025
Request for Continued Examination
Jan 21, 2025
Response after Non-Final Action
Mar 22, 2025
Non-Final Rejection — §103
Jun 27, 2025
Response Filed
Aug 25, 2025
Final Rejection — §103 (current)

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Prosecution Projections

7-8
Expected OA Rounds
78%
Grant Probability
99%
With Interview (+24.8%)
2y 8m
Median Time to Grant
High
PTA Risk
Based on 161 resolved cases by this examiner. Grant probability derived from career allow rate.

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