DETAILED ACTION
1. This office action is in the reply to a divisional application No. 18/824,792 filed on September 04, 2024. Claims 1-9 are submitted for examination. Claim 1 is independent.
Notice of Pre-AIA or AIA Status
2. The present application, filed on or after March 16, 2013, is being examined under the first inventor to file provisions of the AIA .
Priority
3. This application filed on 09/04/2024 is a Divisional of 17817931, filed 08/05/2022, now U.S. Patent # 12120252. 17817931 Claims Priority from Provisional Application 63271727, filed 10/26/2021. 17817931 Claims Priority from Provisional Application 63244857, filed 09/16/2021. 17817931 Claims Priority from Provisional Application 63238890, filed 08/31/2021. 17817931 Claims Priority from Provisional Application 63229924, filed 08/05/2021.
Information Disclosure Statement
4. No information disclosure statements (IDS) is submitted for this application.
Drawings
5. The drawings filed on September 4, 2024 are accepted.
Specification
6. The specification filed on September 4, 2024 is also accepted.
Claim Rejections - 35 USC § 103
7. 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.
The factual inquiries set forth in Graham v. John Deere Co., 383 U.S. 1, 148 USPQ 459 (1966), that are applied for establishing a background for determining obviousness under 35 U.S.C. 103 are summarized as follows:
1. Determining the scope and contents of the prior art.
2. Ascertaining the differences between the prior art and the claims at issue.
3. Resolving the level of ordinary skill in the pertinent art.
4. Considering objective evidence present in the application indicating obviousness or non-obviousness.
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 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.
8. Claims 1-3 are rejected under 35 U.S.C. 103 as being unpatentable over Bjorn Markus Jakobsson (herein after referred as Jakobsson) (US Publication No. 2019/0324995 A1) (Published on Oct. 24, 2019) in view of NPL document, titled, “Bitcoin: A Peer-to-Peer Electronic Cash System” by Satoshi Nakamoto (2008) (herein after referred as Nakamoto).
The following is referring to independent claim 1:
As per independent claim 1, Jakobsson discloses a device configured [Para. 0003, an apparatus comprises at least one processing device comprising a processor coupled to a memory. The at least one processing device implements a mining operator entity configured. The apparatus comprising the processing device implementing a mining operator entity meets the limitation, “device”] to implement a distributed ledger [Para. 0003, an apparatus comprises at least one processing device comprising a processor coupled to a memory. The at least one processing device implements a mining operator entity configured to instantiate one or more mining instances configured to generate one or more proofs of space …in response to a challenge, the challenge being computed at least in part from one or more ledger values of a distributed ledger.] capable of immutably recording a hash chain [Para. Para. 0023, a miner then computes a collection of leaves in a Merkle tree from s by applying a one-way function to s. For example, if the leaves are numbered 0 . . . n−1, the miner generates the jth Merkle leaf as f(s,j), where f is a one-way function such as a cryptographic hash function….., f is the function SHA256. As a result, an array of n leaves are generated, ”… the leaves, n internal node values are generated by applying, to each leaf, a one-way function such as a hash function h. These n internal nodes are then concatenated pairwise, resulting in n/2 pairs, where each such pair is then hashed, resulting in n/2 internal nodes on the next level. This is repeated until only one resulting value is generated, where this resulting value will represent all the n Merkle leaf values generated from s. The Merkle structure/tree that is produced by repeated hashing described in para. 0023-0024 meets the limitation, “hash chain”. Furthermore, Para. 0026, “a witness corresponds to the triple (P, pk, i), and is submitted by the miner to the ledger along with a Merkle signature using public key pk on the most recent set of transactions T that have not been signed in previous ledger entries… “To verify a ledger entry of this type, a verifier generates a leaf from (R, P, pk, i), determines that this leaf value matches the challenge c, and verifies that the associated Merkle signature using pk is a valid signature on the concatenation of the most recent ledger entry and the set T′ of transactions signed in the most recent ledger entry”. Examiner Note: each ledger entry contains -a Merkle signature (which commits to the entire Merkle hash structure: and it itself part of the distributed ledger. This meets the “immutably recording a hash chain” since once the entry with the Merkle signature is added, the committed Merkle tree (hash chain) is locked and verifiable], the device [Figure 9, ref. 902-1, “processing device”] comprising: a network interface [Figure 9, ref. 914, “network interface”]; memory [Figure 9, ref 912, “Memory”]; and a processor [Figure 9, ref. 910, “processor”], the processor configured to:
obtain a ledger entry [ Para. 0025, see how the verifier obtains/retrieve and verify T, the transaction set with is part of ledger entry/Figure 6. “To verify a ledger value, a verifier verifies the Merkle signature on the provided message (P,T) using public key pk, and verifies that T corresponds to a set of posted value transactions” where T is set of transaction. Para. 0027, “T is the set of transactions or references to these”. Figure 6, ref. Transaction set 615 which is part of ledger entry 610; Transaction Set T 625 which also contains “event notification” is part of ledger entry 620… and Figure 6, ref. 610, 620, 630 and 640/ledger entry], the ledger entry Figure 6, ref. 610, 620, 630 and 640/ledger entry] comprising: a hash chain [Para. 0027, The ledger entry comprises values (leafi, pk1, pk2, P, i, sig1, sig2, T) where pk1 is the Merkle public key for the first Merkle signature sig1, pk2 is the Merkle public key for the second signature sig2, and T is the set of transactions or references to these. Para. 0026, Merkle signature using public key pk on the most recent set of transactions T…. Where “leafi/lowest level of the hash is computed as a hash h of (R, P, pk, i)” and I is leaf position. Sig 1= sig1 is a signature of portions of a previous ledger entry and commits the entire Merkle tree. Sig 2 also commits entire Merkle tree. Examiner Note: Leafi+ i+sig-+sig 2 they are hash chain component in the ledger entity. See for instance Para. Para. 0023, a miner then computes a collection of leaves in a Merkle tree from s by applying a one-way function to s. For example, if the leaves are numbered 0 . . . n−1, the miner generates the jth Merkle leaf as f(s,j), where f is a one-way function such as a cryptographic hash function….., f is the function SHA256. As a result, an array of n leaves are generated, ”… the leaves, n internal node values are generated by applying, to each leaf, a one-way function such as a hash function h. These n internal nodes are then concatenated pairwise, resulting in n/2 pairs, where each such pair is then hashed, resulting in n/2 internal nodes on the next level. This is repeated until only one resulting value is generated, where this resulting value will represent all the n Merkle leaf values generated from s. The Merkle structure/tree that is produced by repeated hashing described in para. 0023-0024 which is part of ledger entry such as Leafi+ i+sig-+sig 2 meets the limitation, “hash chain”]; and an event [Figure 6, ref. 625, Transaction set T which also contains “event notification” 626 which is part of the ledger entry 620, corresponds to the limitation “event”. Para. 0027, The ledger entry comprises values (leafi, pk1, pk2, P, i, sig1, sig2, T) where …T is the set of transactions or references. and Para. 0025 ,…T corresponds to a set of posted value transactions]
obtain a challenge using a cryptographic system [Para. 0024, “When a miner receives/obtains a challenge c”] wherein the challenge is based on the hash chain [See the following where challenge C is validated based on the leaves which is hash chain. Para. 0024, “When a miner receives a challenge c, it determines what leaf matches the challenge using a matching function. If a leaf value leafi matches c,” and para. 0026, “a leaf value leafi is computed as a hash h of (R, P, pk, i)”, and the leafi is part of the hash chain. See for instance Para. 0023, a miner then computes a collection of leaves in a Merkle tree from s by applying a one-way function to s. For example, if the leaves are numbered 0 . . . n−1, the miner generates the jth Merkle leaf as f(s,j), where f is a one-way function such as a cryptographic hash function….., f is the function SHA256. As a result, an array of n leaves are generated, ”… the leaves, n internal node values are generated by applying, to each leaf, a one-way function such as a hash function h. These n internal nodes are then concatenated pairwise, resulting in n/2 pairs, where each such pair is then hashed, resulting in n/2 internal nodes on the next level. This is repeated until only one resulting value is generated, where this resulting value will represent all the n Merkle leaf values generated from s. The Merkle structure/tree that is produced by repeated hashing described in para. 0023-0024 which is part of ledger entry such as Leafi+ i+sig-+sig 2 meets the limitation, “hash chain”] and the event [Para. 0025, a verifier verifies the Merkle signature on the provided message (P,T) using public key pk, and verifies that T corresponds to a set of posted value transactions. Figure 6, ref. 625, Transaction set T which also contains “event notification” 626 which is part of the ledger entry 620, corresponds to the limitation “event”. Para. 0027, The ledger entry comprises values (leafi, pk1, pk2, P, i, sig1, sig2, T) where …T is the set of transactions or references. and Para. 0025 ,…T corresponds to a set of posted value transactions];
Jakobsson doesn’t explicitly disclose the limitation, “broadcast a block that incorporates the ledger entry to securely add the block to a distributed ledger, wherein the block is capable of being validated by using a cryptographic system to obtain a proof based on the challenge”
However, Nakamoto explicitly discloses: broadcast a block that incorporates the ledger entry [Page 3, 5, 1-2. 1) New transactions are broadcast to all nodes. 2) Each node collects new transactions into a block] to securely add the block to a distributed ledger [Page 5, 8, “.. blocks added after it further confirm the network has accepted it” Page 3, 5. Network; 2-4, 3) 2) Each node collects new transactions into a block. Each node works on finding a difficult proof-of-work for its block. 4) When a node finds a proof-of-work, it broadcasts the block to all nodes. Examiner Note: In the Nakamoto paper, a block is added through a Proof-of-Work (PoW) competition where miners solve a hard math puzzle /challenge (finding a nonce) for a block of transactions; the winner broadcasts the solved block, other nodes verify the solution and transactions, then link it to the longest chain, reinforcing the network's distributed ledger and securing transactions through computational effort and economic incentives]
wherein the block is capable of being validated by using a cryptographic system to obtain a proof based on the challenge [Page 3, 4, “Proof-of-Work” and 5. Network, shows how miners are competing to solve and validate the challenge/Proof-of-work, “The proof-of-work involves scanning for a value that when hashed, such as with SHA-256, the hash begins with a number of zero bits” Note: this is the computational puzzle/challenge. Page 3. 5. “Network”, 3-5, 3) Each node works on finding a difficult proof-of-work for its block. 4) When a node finds a proof-of-work, it broadcasts the block to all nodes 5) Nodes accept the block only if all transactions in it are valid.”. Nodes always consider the longest chain to be the correct one and will keep working on extending it. Examiner Note: In the Nakamoto paper, a block is validated through a Proof-of-Work (PoW) consensus mechanism: nodes collect transactions, miners race to solve a difficult computational puzzle/corresponds to the claim limitation “challenge” (finding a nonce that produces a hash below a target), the first to solve it broadcasts the block, other nodes verify the block's validity (transactions are valid, not spent)]
Jakobsson and Nakamoto are an analogous in the same field of endeavor as they both address data in distributed ledger using cryptographic proof.
It would have been obvious to a person having ordinary skill in the art before the effective filing date of the claimed invention to implement in the challenge-verified ledger entry system of Jakobsson, a broadcasting and validation rules such as “broadcast a block that incorporates the ledger entry to securely add the block to a distributed ledger, wherein the block is capable of being validated by using a cryptographic system to obtain a proof based on the challenge” as per teaching of Nakamoto for enhancing the security of the system through a combination of decentralization, cryptography, and economic incentives. [Nakamoto, Abstract, The key security mechanisms are designed to allow a decentralized transactions between two parties without the need for a trusted third party like a bank..]
The following is referring to dependent claims 2-3:
As per dependent claim 2, the combination of Jakobsson and Nakamoto discloses the device as applied to claim 1 above. Furthermore, Jakobsson discloses the device, wherein the proof is generated based on an iterative process [Para. 0023, “a miner selects one or more seed values, each represented by a value s, and then computes a collection of leaves in a Merkle tree from s by applying a one-way function to s. For example, if the leaves are numbered 0 . . . n−1, the miner generates the jth Merkle leaf as f(s,j), where f is a one-way function such as a cryptographic hash function. In some embodiments, f is the function SHA256. As a result, an array of n leaves are generated, where n is preferably a power of two. From the leaves, n internal node values are generated by applying, to each leaf, a one-way function such as a hash function h. These n internal nodes are then concatenated pairwise, resulting in n/2 pairs, where each such pair is then hashed, resulting in n/2 internal nodes on the next level. This is repeated until only one resulting value is generated”. Examiner Note: Hash tree in Merkle tree is iterative hashing each hash is computed in sequence/repeatedly, which corresponds to the claim limitation, “iterative process”]
As per dependent claim 3, the combination of Jakobsson and Nakamoto discloses the device as applied to claim 1 above. Furthermore, Jakobsson discloses the device, wherein the challenge is further based on a hardness value [Abstract, the personalized challenge having an associated difficulty/hardness value determined based at least in part on a comparison of the designated amount of storage available for generating the proofs of space and a maximum amount of storage for a mining instance in the proof of space based mining system. Para, 0045, challenge may be a function of at least one of: the information associated with a mining instance, which is also referred to as the graph; the size of the graph; the Merkle tree associated with the graph, which is also referred to as a commitment to the graph; and a global difficulty parameter/hardness value that is used to control all personalized challenges at the same time. An example of the global difficulty parameter is an offset value that is used to modify the difficulty of all personalized challenges, e.g., by doubling their difficulty/hardness value, reducing their difficulty by 50%, etc.]
9. Claims 4-7 are rejected under 35 U.S.C. 103 as being unpatentable over Bjorn Markus Jakobsson (herein after referred as Jakobsson) (US Publication No. 2019/0324995 A1) (Published on Oct. 24, 2019) in view of NPL document, titled, “Bitcoin: A Peer-to-Peer Electronic Cash System” by Satoshi Nakamoto (2008) (herein after referred as Nakamoto) and further in view of Rahul Suraparaju (herein after referred as Suraparaju) (US Pub. No. 20190306190 A1) (Pub. Date: Oct. 3,2019).
As per dependent claim 4, the combination of Jakobsson and Nakamoto discloses the device as applied to claim 1 above. Furthermore, Jakobsson discloses the device, wherein the challenge is further based on a hardness value [Abstract, the personalized challenge having an associated difficulty/hardness value determined based at least in part on a comparison of the designated amount of storage available for generating the proofs of space and a maximum amount of storage for a mining instance in the proof of space based mining system. Para, 0045, challenge may be a function of at least one of: the information associated with a mining instance, which is also referred to as the graph; the size of the graph; the Merkle tree associated with the graph, which is also referred to as a commitment to the graph; and a global difficulty parameter that is used to control all personalized challenges at the same time. An example of the global difficulty parameter is an offset value that is used to modify the difficulty of all personalized challenges, e.g., by doubling their difficulty/hardness value, reducing their difficulty by 50%, etc.]
The combination of Jakobsson and Nakamoto doesn’t explicitly discloses:
“wherein the hardness value is modified based on an occurrence of at least one collision associated with the event”
However, Suraparaju discloses: “wherein the hardness value is modified based on an occurrence of at least one collision associated with the event” [Abstract, “A modified mining algorithm of the conventional bitcoin system adopts, during some periods of time, a lower difficulty for proof-of-work (PoW) than the default difficulty of the conventional bitcoin system, while implementing a malicious fork detection mechanism to monitor the bitcoin blockchain during periods of reduced difficulty”.. “If a malicious fork is found, the mining difficulty is increased back to the default value for a period of time” Examiner Note: A malicious fork is a collision in the ledger (two conflicting branches) when such a collision is detected, the difficulty (hardness value) is increased back to default. This corresponds to “hardness value is modified based occurrence of at least one collision associated with the event”]
Jakobsson, Nakamoto and Suraparaju are an analogous in the same field of endeavor as they all address data in distributed ledger using cryptographic proof.
It would have been obvious to a person having ordinary skill in the art before the effective filing date of the claimed invention to implement in the challenge-verified ledger entry system of Jakobsson and Nakamoto, a modification of hardness based on a fork/collision occurrence such as “the hardness value is modified based on an occurrence of at least one collision associated with the event” as per teaching of Suraparaju for enhancing the security of the system by greatly reducing the probability of successful attacks on the blockchain, the attack being malicious miners attempting to generate valid blocks with fabricated transaction data and to have the malicious blocks being accepted as a part of the longest chain without limiting the capacity of the bitcoin blockchain [Suraparaju, para. 0005, This PoW scheme greatly reduces the probability of successful attacks on the blockchain, the attack being malicious miners attempting to generate valid blocks with fabricated transaction data and to have the malicious blocks being accepted as a part of the longest chain. However, it also limits the capacity of the bitcoin blockchain (i.e. the amount of transaction data that can be recorded per unit time)]
As per dependent claim 5, the combination of Jakobsson and Nakamoto discloses the device as applied to claim 1 above. Furthermore, Jakobsson discloses the device, wherein the challenge is based on a hardness value [[Abstract, the personalized challenge having an associated difficulty/hardness value determined based at least in part on a comparison of the designated amount of storage available for generating the proofs of space and a maximum amount of storage for a mining instance in the proof of space based mining system. Para, 0045, challenge may be a function of at least one of: the information associated with a mining instance, which is also referred to as the graph; the size of the graph; the Merkle tree associated with the graph, which is also referred to as a commitment to the graph; and a global difficulty parameter that is used to control all personalized challenges at the same time. An example of the global difficulty parameter is an offset value that is used to modify the difficulty of all personalized challenges, e.g., by doubling their difficulty/hardness value, reducing their difficulty by 50%, etc.]
The combination of Jakobsson and Nakamoto doesn’t explicitly discloses:
“wherein the challenge is further based on a hardness value and wherein the hardness value is modified based on a number of ledger closings”
However, Suraparaju explicitly discloses: “wherein a hardness value and wherein the hardness value is modified based on a number of ledger closings” [Para. 0010, (d) after adding a predefined number of blocks to the main blockchain, performing a malicious fork detection process. Abstract, “A modified mining algorithm of the conventional bitcoin system adopts, during some periods of time, a lower difficulty for proof-of-work (PoW) than the default difficulty of the conventional bitcoin system, while implementing a malicious fork detection mechanism to monitor the bitcoin blockchain during periods of reduced difficulty”.. “If a malicious fork is found, the mining difficulty is increased back to the default value for a period of time. The default difficulty corresponds to 2016 blocks every 14 days, while the reduced difficulty corresponds to 2016 blocks every 10 days.” Examiner Note: any operation that finalizes a group of transactions and commits to the ledger meets the limitation of ledger closings. In Surapaju, a block collects a set of transactions, after validation, the block is finalized and a predefined number of blocks are added to the chain. This is the same as closing a ledger. ]
Jakobsson, Nakamoto and Suraparaju are an analogous in the same field of endeavor as they all address data in distributed ledger using cryptographic proof.
It would have been obvious to a person having ordinary skill in the art before the effective filing date of the claimed invention to implement in the challenge-verified ledger entry system of Jakobsson and Nakamoto, a modification of hardness based on completing of adding a predefined number of blocks into the ledger/block closure such as “wherein a hardness value and wherein the hardness value is modified based on a number of ledger closings” as per teaching of Suraparaju for enhancing the security of the system by greatly reducing the probability of successful attacks on the blockchain, the attack being malicious miners attempting to generate valid blocks with fabricated transaction data [Suraparaju, para. 0005, This PoW scheme greatly reduces the probability of successful attacks on the blockchain, the attack being malicious miners attempting to generate valid blocks with fabricated transaction data and to have the malicious blocks being accepted as a part of the longest chain.]
As per dependent claim 6, the combination of Jakobsson and Nakamoto discloses the device as applied to claim 1 above. Furthermore, Jakobsson discloses the device, wherein the challenge is based on a hardness value [Abstract, the personalized challenge having an associated difficulty/hardness value determined based at least in part on a comparison of the designated amount of storage available for generating the proofs of space and a maximum amount of storage for a mining instance in the proof of space based mining system. Para, 0045, challenge may be a function of at least one of: the information associated with a mining instance, which is also referred to as the graph; the size of the graph; the Merkle tree associated with the graph, which is also referred to as a commitment to the graph; and a global difficulty parameter that is used to control all personalized challenges at the same time. An example of the global difficulty parameter is an offset value that is used to modify the difficulty of all personalized challenges, e.g., by doubling their difficulty/hardness value, reducing their difficulty by 50%, etc.]
The combination of Jakobsson and Nakamoto doesn’t explicitly discloses:
“wherein the hardness value is modified based on a change in system time”
However, Suraparaju discloses: “wherein the hardness value is modified based on a change in system time” [Para.0004, s more miners join the bitcoin network and compete to generate valid blocks, the average time it takes for a valid block to be generated will decrease (i.e. the rate of block generation will increase). The bitcoin system is designed so that the difficulty target is adjusted every 2016 blocks, to a value such that the previous 2016 blocks would have been generated in 14 days (i.e. an average rate of approximately one block every 10 minutes) had every miner been mining at that difficulty/hardness. This keeps the average rate of block generation approximately constant (approximately one block every 10 minutes) over time. Claim 1. “for a predefined time period, performing mining operation using a default mining difficulty index to add blocks to the main blockchain, without performing the malicious fork detection process, the default mining difficulty index/hardness being more difficult than the reduced mining difficulty index. Examiner Note: Para. 0004 and abstract and claim 1, teaches difficulty/hardness value that changes to maintain a target time interval. If blocks are generated faster than expected, the difficulty increases, and if blocks are generated slower than expected, the difficulty decreases…A time interval measures the duration between two points in system time. Thus, this meets the limitation, “the hardness value is modified based on a change in system time’]
Jakobsson, Nakamoto and Suraparaju are an analogous in the same field of endeavor as they all address data in distributed ledger using cryptographic proof.
It would have been obvious to a person having ordinary skill in the art before the effective filing date of the claimed invention to implement in the challenge-verified ledger entry system of Jakobsson and Nakamoto, a modification of hardness based on time interval or system clock such as “wherein the hardness value is modified based on a change in system time” as per teaching of Suraparaju for enhancing the security of the system by greatly reducing the probability of successful attacks on the blockchain, the attack being malicious miners attempting to generate valid blocks with fabricated transaction data [Suraparaju, para. 0005, This PoW scheme greatly reduces the probability of successful attacks on the blockchain, the attack being malicious miners attempting to generate valid blocks with fabricated transaction data and to have the malicious blocks being accepted as a part of the longest chain.]
As per dependent claim 7, the combination of Jakobsson and Nakamoto discloses the device as applied to claim 1 above. Furthermore, Jakobsson discloses the device, wherein the challenge is based on a hardness value [Abstract, the personalized challenge having an associated difficulty/hardness value determined based at least in part on a comparison of the designated amount of storage available for generating the proofs of space and a maximum amount of storage for a mining instance in the proof of space based mining system. Para, 0045, challenge may be a function of at least one of: the information associated with a mining instance, which is also referred to as the graph; the size of the graph; the Merkle tree associated with the graph, which is also referred to as a commitment to the graph; and a global difficulty parameter that is used to control all personalized challenges at the same time. An example of the global difficulty parameter is an offset value that is used to modify the difficulty of all personalized challenges, e.g., by doubling their difficulty/hardness value, reducing their difficulty by 50%, etc.]
The combination of Jakobsson and Nakamoto doesn’t explicitly discloses:
“wherein the hardness value is modified based on an absence of at least one collision associated with the event”
However, Suraparaju explicitly discloses: “wherein the hardness value is modified based on an absence of at least one collision associated with the event” [Para.0010, (e) in response to no malicious fork being detected/no collision or absence of collision in the malicious fork detection process in step (d), repeating steps (c) c) performing mining operation using the reduced mining difficulty index/reducing the hardness value]
Jakobsson, Nakamoto and Suraparaju are an analogous in the same field of endeavor as they all address data in distributed ledger using cryptographic proof.
It would have been obvious to a person having ordinary skill in the art before the effective filing date of the claimed invention to implement in the challenge-verified ledger entry system of Jakobsson and Nakamoto, a modification of hardness based on absence of collision such as “the hardness value is modified based on an absence of at least one collision associated with the event” as per teaching of Suraparaju for enhancing the security of the system by greatly reducing the probability of successful attacks on the blockchain, the attack being malicious miners attempting to generate valid blocks with fabricated transaction data and to have the malicious blocks being accepted as a part of the longest chain [Suraparaju, para. 0005, This PoW scheme greatly reduces the probability of successful attacks on the blockchain, the attack being malicious miners attempting to generate valid blocks with fabricated transaction data and to have the malicious blocks being accepted as a part of the longest chain. However, it also limits the capacity of the bitcoin blockchain (i.e. the amount of transaction data that can be recorded per unit time)]
10. Claims 8-9 are rejected under 35 U.S.C. 103 as being unpatentable over Bjorn Markus Jakobsson (herein after referred as Jakobsson) (US Publication No. 2019/0324995 A1) (Published on Oct. 24, 2019) in view of NPL document, titled, “Bitcoin: A Peer-to-Peer Electronic Cash System” by Satoshi Nakamoto (2008) (herein after referred as Nakamoto) and further in view Anatoly Yakovenko (Yakovenko) (International application, Publication No. WO2019113495A1, Pub. Date: June 13, 2019.
The following is referring to independent claims 8-9:
As per dependent claim 8, the combination of Jakobsson and Nakamoto discloses the device as applied to claim 1 above. Furthermore, Jakobsson discloses “the hash chain” [Para. Para. 0023, a miner then computes a collection of leaves in a Merkle tree from s by applying a one-way function to s. For example, if the leaves are numbered 0 . . . n−1, the miner generates the jth Merkle leaf as f(s,j), where f is a one-way function such as a cryptographic hash function….., f is the function SHA256. As a result, an array of n leaves are generated, ”… the leaves, n internal node values are generated by applying, to each leaf, a one-way function such as a hash function h. These n internal nodes are then concatenated pairwise, resulting in n/2 pairs, where each such pair is then hashed, resulting in n/2 internal nodes on the next level. This is repeated until only one resulting value is generated, where this resulting value will represent all the n Merkle leaf values generated from s. The Merkle structure/tree that is produced by repeated hashing described in para. 0023-0024 meets the limitation, “hash chain”. Furthermore Nakamot on at least abstract teaches “hash chain”, “A purely peer-to-peer version of electronic cash would allow online payments to be sent directly from one party to another without going through a financial institution. Digital signatures provide part of the solution, but the main benefits are lost if a trusted third party is still required to prevent double-spending. We propose a solution to the double-spending problem using a peer-to-peer network. The network timestamps transactions by hashing them into an ongoing chain of hash-based proof-of-work, forming a record that cannot be changed without redoing the proof-of-work”. The longest chain not only serves as proof of the sequence of events witnessed, but proof that it came from the largest pool of CPU power.]
The combination of Jakobsson and Nakamoto doesn’t explicitly discloses:
“wherein the hash chain is used for a Proof of History computation”
However, Yakovenko discloses: ” wherein the hash chain is used for a Proof of History computation” [Figure 10-12 and para. 0026-0027, [0026] Figure, ref. “Proof of History Hash” and Fig. 11 shows the system architecture showing the currently active Proof of History generator node and downstream nodes; [0027] Fig. 12 shows the Proof of History generator node of Fig. 11 with incoming and outgoing traffic; and Para. 0083, continuous chain of hashes 0006, Such a cryptographically secure function may be completely executed to generate an output, and such function may be run iteratively in a sequence so that its output from a previous execution may be used as the input in the current execution. The current output and/or how many times it has been executed or called can be periodically recorded].
Jakobsson, Nakamoto and Yakovenko are an analogous in the same field of endeavor as they all address data in distributed ledger using cryptographic proof.
It would have been obvious to a person having ordinary skill in the art before the effective filing date of the claimed invention to implement in the challenge-verified ledger entry system of Jakobsson and Nakamoto, a Proof of History computation such as “wherein the hash chain is used for a Proof of History computation” as per teaching of Yakovenko for enhancing the security of the system by disabling any misbehaving validators. [Yakovenko, para. 0092, a specific instance of proof of stake permits quick confirmation of the current sequence produced by a proof of history (PoH) generator, for voting and selecting the next proof of history generator, and for disabling any misbehaving validators. ]
As per dependent claim 9, the combination of Jakobsson and Nakamoto discloses the device as applied to claim 1 above. Furthermore, Jakobsson discloses “the hash chain” [Para. Para. 0023, a miner then computes a collection of leaves in a Merkle tree from s by applying a one-way function to s. For example, if the leaves are numbered 0 . . . n−1, the miner generates the jth Merkle leaf as f(s,j), where f is a one-way function such as a cryptographic hash function….., f is the function SHA256. As a result, an array of n leaves are generated, ”… the leaves, n internal node values are generated by applying, to each leaf, a one-way function such as a hash function h. These n internal nodes are then concatenated pairwise, resulting in n/2 pairs, where each such pair is then hashed, resulting in n/2 internal nodes on the next level. This is repeated until only one resulting value is generated, where this resulting value will represent all the n Merkle leaf values generated from s. The Merkle structure/tree that is produced by repeated hashing described in para. 0023-0024 meets the limitation, “hash chain”. Furthermore, Nakamot on at least abstract teaches “hash chain”, “A purely peer-to-peer version of electronic cash would allow online payments to be sent directly from one party to another without going through a financial institution. Digital signatures provide part of the solution, but the main benefits are lost if a trusted third party is still required to prevent double-spending. We propose a solution to the double-spending problem using a peer-to-peer network. The network timestamps transactions by hashing them into an ongoing chain of hash-based proof-of-work, forming a record that cannot be changed without redoing the proof-of-work”. The longest chain not only serves as proof of the sequence of events witnessed, but proof that it came from the largest pool of CPU power.]
The combination of Jakobsson and Nakamoto doesn’t explicitly discloses:
“wherein the hash chain is used to create a relative order between recorded events, wherein the recorded events comprise the event”
However, Yakovenko explicitly discloses: “wherein the hash chain is used to create a relative order between recorded events, wherein the recorded events comprise the event” [Para. 0006, A cryptographically secure hash function may be used herein whose output cannot be predicted from the input. Such a cryptographically secure function may be completely executed to generate an output, and such function may be run iteratively in a sequence so that its output from a previous execution may be used as the input in the current execution. The current output and/or how many times it has been executed or called can be periodically recorded. The output can then be recomputed and verified by external computers in parallel by checking one or more iterations in parallel on separate computer(s). Data can be timestamped into the sequence by recording the data and the index when the data is mixed into the sequence. Such timestamp then may guarantee that the data was created sometime before a next output of the secure function is generated in the sequence. Multiple clocks can synchronize amongst each other by mixing their state into each other’s sequences. Para. 0007, The present disclosure may advantageously enable creation of a temporal order of events that does not have to be trusted by any of the external clients. Note the sequence of hashes is the hash chain.]
Jakobsson, Nakamoto and Yakovenko are an analogous in the same field of endeavor as they all address data in distributed ledger using cryptographic proof.
It would have been obvious to a person having ordinary skill in the art before the effective filing date of the claimed invention to implement in the challenge-verified ledger entries system of Jakobsson and Nakamoto, sequence of recorded events such as “wherein the hash chain is used to create a relative order between recorded events, wherein the recorded events comprise the event” as per teaching of Yakovenko for enhancing the security of the system by disabling any misbehaving validators. [Yakovenko, para. 0092, a specific instance of proof of stake permits quick confirmation of the current sequence produced by a proof of history (PoH) generator, for voting and selecting the next proof of history generator, and for disabling any misbehaving validators]
Conclusion
11. The prior art made of record and not relied upon is considered pertinent to applicant's disclosure.
A. US Patent No 10,789,590 B2 Tran discloses a blockchain system with a shared transaction badger, blocks, proof-of-work/proof-of-stake verification and also discloses transaction recorded in a distributed ledger and miners verifying blockes and use of standard hash functions e.g. SHA-256)
B. US Patent No. 10541820B2 Chino discloses methods and systems for generating a new record in a digital ledger include hashing a payload, public key, and signature of a parent record to generate a hash value. A new record is created with a new payload and a new public key. The hash value is combined with the new payload and the new public key to generate a message value. A signature of the new record is generated using the message value and a private key corresponding to the public key of the parent record. The signature of the new record is added to the new record.
C. US Publication No 2017/0075938A1 Black discloses data storage and verification system that provides non-repudiation when hashes of the data are recorded to the blockchain. Data records may be verified in any time interval (e.g., second, day, week, month, year, decade). The Data Storage and Verification Platform can validate data in smaller time intervals, avoiding the need to verify an entire data set which may span decades.
D. US Patent No. 10855445B2 to Gabriel discloses techniques for summarizing data in a distributed system. Embodiments include generating an ordered list of blocks by iterating through a first group of blocks of a hash chain starting at a last block of the hash chain and adding each of the first group of blocks of the hash chain to the ordered list. Embodiments further include generating summary data by applying a summary function to the first group of blocks based on the ordered list.
E. See the other cited references.
Conclusion
12. Any inquiry concerning this communication or earlier communications from the examiner should be directed to SAMSON B LEMMA whose telephone number is 571-272-3806. The examiner can normally be reached on M-F 8am-10pm.
If attempts to reach the examiner by telephone are unsuccessful, the examiner’s supervisor, Shaw Yin Chen can be reached on 571-272-8878. The fax phone number for the organization where this application or proceeding is assigned is 571-273-8300.
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/SAMSON B LEMMA/
Primary Examiner, Art Unit 2498