Decentralized Identifiers (DIDs) are increasingly deployed on distributed ledgers, yet systematic cross-platform evidence on their operational behavior remains limited. We present an empirical benchmarking study of three prominent ledger-based DID methods - Ethereum, Hedera, and XRP Ledger - using reference Software Development Kits (SDKs) under a unified experimental setup. We measure latency, transaction cost, and on-chain metadata exposure, normalizing latency by each platform's block or consensus interval and cost by its native value transfer fee. Privacy leakage is quantified using a Metadata-Leakage Score (MLS), an entropy-based measure expressed in bits per operation. Our results reveal distinct architectural trade-offs. Ethereum enables near-instant, off-chain DID creation, but incurs the highest latency and cost for on-chain lifecycle operations. XRPL delivers deterministic and stable latency with fixed, low fees, yet exhibits higher metadata leakage due to more verbose transaction payloads. Hedera achieves the lowest on-chain latency and low fees with minimal metadata leakage, while occasional variance arises from SDK-side processing and confirmation pipelines. Overall, the findings show that ledger architecture and SDK workflows play a major role in shaping DID latency, cost, and metadata exposure, complementing the effects of the underlying consensus mechanism. These results provide evidence-based insights to support informed selection and configuration of DID systems under performance and privacy constraints.

翻译：去中心化标识符（DIDs）在分布式账本上的部署日益增多，然而关于其运行行为的系统性跨平台实证证据仍然有限。本研究对三种主流的基于账本的DID方法——Ethereum、Hedera和XRP Ledger——进行了实证基准测试，在统一的实验设置下使用参考软件开发工具包（SDKs）。我们测量了延迟、交易成本和链上元数据暴露情况，其中延迟通过各平台的区块或共识间隔进行归一化，成本通过其原生价值转移费用进行归一化。隐私泄露通过元数据泄露分数（MLS）进行量化，这是一种基于熵的度量，以比特/操作表示。我们的结果揭示了不同的架构权衡。Ethereum支持近乎即时的链下DID创建，但其链上生命周期操作具有最高的延迟和成本。XRPL提供确定且稳定的延迟以及固定、低廉的费用，但由于交易负载更为冗长，表现出更高的元数据泄露。Hedera实现了最低的链上延迟和低费用，同时元数据泄露最小，但偶尔的波动源于SDK端处理和确认流水线。总体而言，研究结果表明，账本架构和SDK工作流在塑造DID延迟、成本和元数据暴露方面起着主要作用，补充了底层共识机制的影响。这些结果为在性能和隐私约束下支持DID系统的明智选择和配置提供了基于证据的见解。