With the widespread adoption of digital twin (DT) technology in cross-domain data sharing scenarios, ensuring secure and efficient search over encrypted data has become a significant challenge. This article proposes a blockchain-based searchable encryption scheme tailored for DTs, supporting privacy-preserving keyword search, verifiable data access, and decentralized trust establishment. The scheme collects real-time data streams from digital sensors and devices to construct unified DT records for intelligent analytics and decision-making. The scheme integrates lightweight searchable encryption with blockchain-based trapdoor delegation and ciphertext-level indexing, enabling secure and low-complexity keyword matching. By introducing a delegated trapdoor mechanism, users can authorize repeated keyword queries via a single token, thereby minimizing communication and computational costs. Additionally, a blockchain-driven key generation protocol based on distributed voting eliminates reliance on centralized authorities and ensures transparent, auditable key management. Moreover, encrypted records are stored in IPFS, resolving the storage limitations of blockchain and preserving verifiable data availability. The trapdoor delegation records and result verification parameters are committed on-chain, enabling query correctness checking and traceable access control. Under the ciphertext indistinguishability (CI) and trapdoor indistinguishability (TI) security models, the proposed scheme is formally proven to achieve CI and trapdoor privacy, providing resistance to adaptive insider keyword guessing attacks. Compared with existing schemes, it offers stronger privacy guarantees with lower overhead, supporting scalable and secure DT data sharing.

Industrial Internet of Things (IIoT) enables highly automated and intelligent cross-domain communication. Due to varying computational capabilities and security requirements, cross-domain IIoT data sharing involves the design of security protocols using different cryptosystems. Attribute-based searchable encryption enables fine-grained access control and ciphertext retrieval, but existing schemes are primarily designed on a singular cryptosystem, lacking support for searches on heterogeneous ciphertext. Moreover, related schemes still suffer from technical challenges, such as the single point bottleneck, caused by a single attribute authority, issues with attribute updates, and forward secrecy attacks. In this article, we propose an attribute-based heterogeneous data privacy sharing (AB-HDPS) scheme for blockchain-assisted IIoT. Attribute-authorized users within a public key infrastructure cryptosystem can search ciphertext from data owners in a certificateless cryptosystem. The scheme utilizes multiple authorities to generate attribute keys, employs a glass-box traceable mechanism to prevent misuse of attribute keys, and implements subset-cover trees for attribute revocation. Specifically, leveraging the immutability of blockchain, the AB-HDPS scheme supports traceability and auditing of user access. Security analysis shows that the AB-HDPS scheme can resist internal keyword guessing and chosen-plaintext attacks, and it satisfies forward security. Comparative experimental simulations demonstrate that the AB-HDPS scheme with outsourced decryption has satisfactory computational performance, and the performance of the blockchain system within the scheme is commendable.

To achieve fine-grained access control and address the data silos challenge in data sharing, the integration of blockchain with attribute-based encryption emerges as a promising solution. Nowadays, the growing interconnectedness among diverse blockchain applications has spurred the need for efficient cross-chain data sharing. However, existing single-authority attribute-based data sharing schemes are not suitable for such cross-chain scenarios involving multiple attribute authorities. Moreover, the frequent requirement for data owners to process cross-chain data requests significantly hampers practicality. In this context, we introduce a novel multi-authority attribute-based proxy re-encryption scheme that enables ciphertext policy updating and supports secure and efficient cross-chain data sharing. By introducing a proxy, the data owner is empowered to delegate access without leaking any valid information and flexibly sells data across blockchains through cross-chain access policies. Besides, our scheme leverages the relay chain to foster a decentralized and trustworthy ecosystem. The adoption of smart contracts automates the cross-chain data sharing process and ensures equitable distribution of benefits among participants. Additionally, our scheme integrates hybrid encryption with the decentralized data hosting platform, substantially mitigating the on-chain storage burden. Security analysis affirms that our scheme is semantically secure and resistant to collusion attack. Performance analysis and simulation experiments demonstrate the excellent efficiency and practicality of our scheme when conducting cross-chain data sharing.

Privacy protection and open sharing are the core of data governance in the AI‐driven era. A common data‐sharing management platform is indispensable in the existing data‐sharing solutions, and users upload their data to the cloud server for storage and dissemination. However, from the moment users upload the data to the server, they will lose absolute ownership of their data, and security and privacy will become a critical issue. Although data encryption and access control are considered up‐and‐coming technologies in protecting personal data security on the cloud server, they alleviate this problem to a certain extent. However, it still depends too much on a third‐party organization’s credibility, the Cloud Service Provider (CSP). In this paper, we combined blockchain, ciphertext‐policy attribute‐based encryption (CP‐ABE), and InterPlanetary File System (IPFS) to address this problem to propose a blockchain‐based security sharing scheme for personal data named BSSPD. In this user‐centric scheme, the data owner encrypts the sharing data and stores it on IPFS, which maximizes the scheme’s decentralization. The address and the decryption key of the shared data will be encrypted with CP‐ABE according to the specific access policy, and the data owner uses blockchain to publish his data‐related information and distribute keys for data users. Only the data user whose attributes meet the access policy can download and decrypt the data. The data owner has fine‐grained access control over his data, and BSSPD supports an attribute‐level revocation of a specific data user without affecting others. To further protect the data user’s privacy, the ciphertext keyword search is used when retrieving data. We analyzed the security of the BBSPD and simulated our scheme on the EOS blockchain, which proved that our scheme is feasible. Meanwhile, we provided a thorough analysis of the storage and computing overhead, which proved that BSSPD has a good performance.

With rapid development of computing technologies, large amount of data are gathered from edge terminals or Internet of Things (IoT) devices, however data trust and security in edge computing environment are very important issues to be considered, especially when the gathered data are fraud or dishonest, or the data are misused or spread without any authorization, which may lead to serious problems. In this article, a blockchain-based trusted data management scheme (called BlockTDM) in edge computing is proposed to solve the above problems, in which we proposed a flexible and configurable blockchain architecture that includes mutual authentication protocol, flexible consensus, smart contract, block and transaction data management, blockchain nodes management, and deployment. The BlockTDM scheme can support matrix-based multichannel data segment and isolation for sensitive or privacy data protection, and moreover, we have designed user-defined sensitive data encryption before the transaction payload stores in blockchain system, and have implemented conditional access and decryption query of the protected blockchain data and transactions through smart contract. Finally, we have evaluated the proposed BlockTDM scheme security, availability, and efficiency with large amount of experiments. Analysis and evaluations manifest that the proposed BlockTDM scheme provides a general, flexible, and configurable blockchain-based paradigm for trusted data management with tamper-resistance, which is suitable for edge computing with high-level security and creditability.