問59
頻出度★★★
複数の取引記録をまとめたデータを順次作成するときに, そのデータに直前のデータのハッシュ値を埋め込むことによって, データを相互に関連付け, 取引記録を矛盾なく改ざんすることを困難にすることで, データの信頼性を高める技術はどれか。
令和元年度 秋期 ITパスポート試験 問59
This question's explanation and your answers so far.
解説
問 59
Incorrectア
LPWA (Low Power Wide Area) is a general term for IoT-oriented wireless communication methods that communicate over a wide area with low power consumption. It is a communication technology that connects devices such as sensors over long distances with low power, and has nothing to do with hash-value-based tamper prevention or the linking of data.
Incorrectイ
SDN (Software-Defined Networking) is a technology that centrally manages the control of network devices with software, allowing the configuration to be changed flexibly. It is a technology for network operation, and is not intended to prevent tampering with transaction records or to ensure the reliability of data.
Incorrectウ
Edge computing is a distributed-processing concept that performs data processing on the “edge” side, close to the users and devices, so as to reduce communication latency and cloud load. It is a technology that distributes where processing takes place, and differs from the mechanism of linking data with hash values to make tampering difficult.
- エ
正解 The correct answer is “エ Blockchain”. Blockchain is a technology that bundles multiple transaction records into “blocks” and links them in a chain by including the hash value of the immediately preceding block in each block. Because a hash value becomes a completely different value if the original data changes even slightly, tampering with one block causes a mismatch with the hash value held by the following blocks, so the inconsistency is exposed in a chain reaction. Rewriting the past without any inconsistency would require regenerating every linked block, which is practically infeasible, and this is what supports the data's tamper resistance and reliability. It is used as the foundational technology for distributed ledgers such as crypto-assets. The stem's phrase “embedding the hash value of the immediately preceding data to associate the pieces of data with one another” refers precisely to this mechanism.
ここがポイント
- Blockchain = a distributed-ledger technology that bundles transaction records into blocks and links them in a chain by embedding the hash value of the immediately preceding block in each block, making tampering difficult.
- A hash value has the property of becoming a completely different value if the original data changes even slightly, and this property is used to achieve consistency checking of the chain and detection of tampering.
用語