The immutability is a crucial property for blockchain applications,however,it also leads to problems such as the inability to revise illegal data on the blockchain and delete private data.Although redactable blockchai...The immutability is a crucial property for blockchain applications,however,it also leads to problems such as the inability to revise illegal data on the blockchain and delete private data.Although redactable blockchains enable on-chain modification,they suffer from inefficiency and excessive centralization,the majority of redactable blockchain schemes ignore the difficult problems of traceability and consistency check.In this paper,we present a Dynamically Redactable Blockchain based on decentralized Chameleon hash(DRBC).Specifically,we propose an Identity-Based Decentralized Chameleon Hash(IDCH)and a Version-Based Transaction structure(VT)to realize the traceability of transaction modifications in a decentralized environment.Then,we propose an efficient block consistency check protocol based on the Bloom filter tree,which can realize the consistency check of transactions with extremely low time and space cost.Security analysis and experiment results demonstrate the reliability of DRBC and its significant advantages in a decentralized environment.展开更多
An instructional management system(IMS)regularly manages student data with a centralized database,which may be prone to single points of failure and data tampering.Blockchain can effectively solve the above problems d...An instructional management system(IMS)regularly manages student data with a centralized database,which may be prone to single points of failure and data tampering.Blockchain can effectively solve the above problems due to its decentralization and immutability.However,the immutability of blockchain restricts the edit of data in some cases(e.g.,incorrect score records).In this paper,we propose an advanced decentralized instructional management framework based on redactable blockchain,wherein chain nodes possess the capability to autonomously revise their initiated transactions with regular chameleon hash functions.Concurrently,system users can anonymously report discrepancies or erroneous entries within the blockchain.When such reports are validated and malicious activities are cofirmed,the review team can undertake decentralized modfications to rectify the malicious content with our proposed scheme.In addition,we conduct a security analysis of the scheme,evaluating its correctness,collision resistance,and claimability.Finally,experimental results demonstrate that the scheme is practical.展开更多
With the popularity of the internet,users hope to better protect their privacy while obtaining network services.However,in the traditional centralized authentication scheme,identity information such as the user's ...With the popularity of the internet,users hope to better protect their privacy while obtaining network services.However,in the traditional centralized authentication scheme,identity information such as the user's private key is generated,stored,and managed by the network operator.Users can't control their identity information,which will lead to a great threat to the privacy of users.Based on redactable blockchain,we propose a fine-grained and fair identity authentication scheme for mobile networks.In our proposed scheme,the user's identity information is generated and controlled by the users.We first propose a notion of score chameleon hash(SCH),which can delete or update the information of illegal users so as to dynamically update the status of users and provide users with more fine-grained and fair services.We propose another notion of self-updating secret sharing(SUSS),which allows users to update the trapdoor and the corresponding hash key after redacting the blockchain without requiring trusted authority to redistribute the trapdoor.Experimental results show that,compared with the immutable blockchain Bitcoin,the redactable blockchain in our identity authentication scheme provides users with fine-grained and fair redacting functions,and can be adopted with a small additional overhead.展开更多
A redactable blockchain allows authorized individuals to remove or replace undesirable content,offering the ability to remove illegal or unwanted information.Access control is a mechanism that limits data visibility a...A redactable blockchain allows authorized individuals to remove or replace undesirable content,offering the ability to remove illegal or unwanted information.Access control is a mechanism that limits data visibility and ensures that only authorized users can decrypt and access encrypted information,playing a crucial role in addressing privacy concerns and securing the data stored on a blockchain.Redactability and access control are both essential components when implementing a regulated consortium blockchain in real-world situations to ensure the secure sharing of data while removing undesirable content.We propose a decentralized consortium blockchain system prototype that supports redactability and access control.Through the development of a prototype blockchain system,we investigate the feasibility of combining these approaches and demonstrate that it is possible to implement a redactable blockchain with access control in a consortium blockchain setting.展开更多
Blockchain technology is generally immutable,but there are limita-tions to the practical application of this feature.Therefore,a redactable blockchain was introduced.Based on the literature and the practical needs of ...Blockchain technology is generally immutable,but there are limita-tions to the practical application of this feature.Therefore,a redactable blockchain was introduced.Based on the literature and the practical needs of redactable blockchains,we propose a new type of chameleon hash function with stronger securityfeatures,aTraceableDecentralizedPolicy-BasedChameleonHash,which is named TDPCH in this paper.Then,the TDPCH is applied to the design of redactable blockchain.Our scheme has a better application scenario,which can help realize the adaptation of the blockchain,and has the security characteristics of decentralization of authority management and accountability of modifiers.展开更多
基金supported in part by the National Key R&D Program of China under project 2022YFB2702901the Guangxi Natural Science Foundation under grants 2024GXNSFDA010064 and 2024GXNSFAA010453+5 种基金the National Natural Science Foundation of China under projects 62172119,62362013,U21A20467 and 72192801Zhejiang Provincial Natural Science Foundation of China under grant LZ23F020012Innovation Project of GUET Graduate Education under grants 2023YCXS070the Guangxi Young Teachers'Basic Ability Improvement Program under grant 2024KY0224Lion Rock Labs of Cyberspace Security under grant LRL24-1-C003one of the research outcomes of the Xiong'an Autonomous and Controllable Blockchain Underlying Technology Platform Project(2020).
文摘The immutability is a crucial property for blockchain applications,however,it also leads to problems such as the inability to revise illegal data on the blockchain and delete private data.Although redactable blockchains enable on-chain modification,they suffer from inefficiency and excessive centralization,the majority of redactable blockchain schemes ignore the difficult problems of traceability and consistency check.In this paper,we present a Dynamically Redactable Blockchain based on decentralized Chameleon hash(DRBC).Specifically,we propose an Identity-Based Decentralized Chameleon Hash(IDCH)and a Version-Based Transaction structure(VT)to realize the traceability of transaction modifications in a decentralized environment.Then,we propose an efficient block consistency check protocol based on the Bloom filter tree,which can realize the consistency check of transactions with extremely low time and space cost.Security analysis and experiment results demonstrate the reliability of DRBC and its significant advantages in a decentralized environment.
基金supported by the Foundation of the Qufu Normal University(No.167-603701)by the Shandong Provincial Natural Science Foundation of Shandong Province,China(No.ZR2023MA049).
文摘An instructional management system(IMS)regularly manages student data with a centralized database,which may be prone to single points of failure and data tampering.Blockchain can effectively solve the above problems due to its decentralization and immutability.However,the immutability of blockchain restricts the edit of data in some cases(e.g.,incorrect score records).In this paper,we propose an advanced decentralized instructional management framework based on redactable blockchain,wherein chain nodes possess the capability to autonomously revise their initiated transactions with regular chameleon hash functions.Concurrently,system users can anonymously report discrepancies or erroneous entries within the blockchain.When such reports are validated and malicious activities are cofirmed,the review team can undertake decentralized modfications to rectify the malicious content with our proposed scheme.In addition,we conduct a security analysis of the scheme,evaluating its correctness,collision resistance,and claimability.Finally,experimental results demonstrate that the scheme is practical.
基金supported by the Natural Science Foundation of Shanghai(20ZR1419700 and 22ZR1481000)Open Foundation of Henan Key Laboratory of Cyberspace Situation Awareness(HNTS2022011)。
文摘With the popularity of the internet,users hope to better protect their privacy while obtaining network services.However,in the traditional centralized authentication scheme,identity information such as the user's private key is generated,stored,and managed by the network operator.Users can't control their identity information,which will lead to a great threat to the privacy of users.Based on redactable blockchain,we propose a fine-grained and fair identity authentication scheme for mobile networks.In our proposed scheme,the user's identity information is generated and controlled by the users.We first propose a notion of score chameleon hash(SCH),which can delete or update the information of illegal users so as to dynamically update the status of users and provide users with more fine-grained and fair services.We propose another notion of self-updating secret sharing(SUSS),which allows users to update the trapdoor and the corresponding hash key after redacting the blockchain without requiring trusted authority to redistribute the trapdoor.Experimental results show that,compared with the immutable blockchain Bitcoin,the redactable blockchain in our identity authentication scheme provides users with fine-grained and fair redacting functions,and can be adopted with a small additional overhead.
基金supported by the National Key Research and Development Program of China(2020YFB1005900)。
文摘A redactable blockchain allows authorized individuals to remove or replace undesirable content,offering the ability to remove illegal or unwanted information.Access control is a mechanism that limits data visibility and ensures that only authorized users can decrypt and access encrypted information,playing a crucial role in addressing privacy concerns and securing the data stored on a blockchain.Redactability and access control are both essential components when implementing a regulated consortium blockchain in real-world situations to ensure the secure sharing of data while removing undesirable content.We propose a decentralized consortium blockchain system prototype that supports redactability and access control.Through the development of a prototype blockchain system,we investigate the feasibility of combining these approaches and demonstrate that it is possible to implement a redactable blockchain with access control in a consortium blockchain setting.
基金supported by the National Natural Science Foundation of China under Grant No.61702570 and 61907042Beijing Natural Science Foundation under Grant No.4194090.
文摘Blockchain technology is generally immutable,but there are limita-tions to the practical application of this feature.Therefore,a redactable blockchain was introduced.Based on the literature and the practical needs of redactable blockchains,we propose a new type of chameleon hash function with stronger securityfeatures,aTraceableDecentralizedPolicy-BasedChameleonHash,which is named TDPCH in this paper.Then,the TDPCH is applied to the design of redactable blockchain.Our scheme has a better application scenario,which can help realize the adaptation of the blockchain,and has the security characteristics of decentralization of authority management and accountability of modifiers.
