Driven by various legal obligations and service requirements, the redactable blockchain was introduced to balance the modifiability and immutability of blockchain technology. However, such a blockchain inevitably generates one or even more acceptable versions for the same block data, enabling malicious full nodes to deceive light/new nodes with old data, and even disrupt the consistency of the blockchain ledger. In this paper, we introduce the concept of verifiable redactable blockchain (VRBC) to provide efficient validity verification for on-chain data. To this end, we design a novel authentication data structure, called blockchain authentication tree (BAT), which employs a chameleon hash function and aggregatable vector commitment to bind continuously-appended blocks. Based on this, we propose an efficient VRBC scheme supporting integrity auditing, which not only allows the light nodes to query and validate on-chain data, but also enables new nodes to check the integrity of the block
Internet of Things (IoT) devices upload their data into the cloud for storage because of their limited resources. However, cloud storage data has been subject to potential integrity threats, and consequently auditing techniques are demanded to ensure the integrity of stored data. Unfortunately, existing auditing approaches require owners to undertake expensive tag calculations, which is unsuitable for resource-constrained IoT devices. To resolve the issue, we present a Fair Cloud Auditing proposal by employing the Blockchain (FCAB). We combine certificateless signatures with the designed dynamic structure to constructively offload the cost of tag computation from the IoT device to the introduced fog node, significantly reducing the local burden. Considering that fog nodes may behave dishonestly during auditing, FCAB enables the IoT device to verify the audit result's authenticity by extracting reliable checking records from the blockchain, thereby achieving auditing fairness, whic
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