辻村 都倭
Blockchain technology is widely used for cryptocurrencies and other applications as an underlying tech nology for reliable data management on decentralized networks, but as the size of blockchains increases, the amount of computation and communication required for transaction verification increases. To ad dress this problem, Agrawal et al. proposed Key-Value Commitments (KVaC), which enables efficient data verification. However, KVaC can distinguish between insert and update operations of key-value pairs, and there is a risk that the frequency and timing of the operations can be inferred from the update information, thus analyzing the trends and intentions of transactions. To address this issue, this study introduces the Oblivious Accumulator. Cryptographic Accumulators that efficiently manage aggregate data are typically aggregate commitment schemes that support the addition and deletion of elements and provide (non-)membership proofs. Oblivious Accumulator furthermore has properties that guarantee element hiding and add-delete indistinguishability. By utilizing the Oblivious Accumulator and treating all update operations as insert operations, we propose a Key-Value Commitment scheme that prevents the identification of operation content in KVaC and improves transaction privacy.
