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Vol. 1 · Ed. 2026
CyberGlossary
日本語
Entry № 088

Attribution Reporting API

Attribution Reporting API とは何ですか?

Attribution Reporting APIA Privacy Sandbox API in Chrome and Android that lets advertisers measure ad conversions across sites without cross-site identifiers, using browser-mediated, noise-injected event-level or aggregated reports.

The Attribution Reporting API (ARA) is the Privacy Sandbox mechanism for measuring ad-driven conversions without exposing cross-site identifiers. Sources (ad clicks or views) are registered on the publisher side; triggers (conversions) are registered on the advertiser side. The browser maintains the join between them locally and, at delayed and randomized intervals, sends one of two kinds of report. Event-level reports return a noisy, low-resolution mapping from a source event to a conversion event, suitable for click attribution. Aggregatable reports go through a separate Aggregation Service running in a trusted execution environment, which adds calibrated noise (differential privacy) before returning aggregate dashboards across many users. Both report types are designed to bound the cross-site information any caller can learn. ARA is one of the central pieces of the post-third-party-cookie measurement story and a focus of regulator attention (CMA, French CNIL, German DPAs). For ad-tech and measurement vendors, integrating ARA requires substantial backend changes for noise budgets, report aggregation, and trust-establishment with the Aggregation Service.

● 例

  1. 01

    An advertiser registers click-trigger and conversion-trigger callbacks; Chrome delivers event-level reports days later, with noise to limit user-level inference.

  2. 02

    A measurement vendor stands up an Aggregation Service in a TEE so that ARA aggregatable reports can be processed into campaign-level dashboards.

● よくある質問

Attribution Reporting API とは何ですか?

A Privacy Sandbox API in Chrome and Android that lets advertisers measure ad conversions across sites without cross-site identifiers, using browser-mediated, noise-injected event-level or aggregated reports. サイバーセキュリティの プライバシーとデータ保護 カテゴリに属します。

Attribution Reporting API とはどういう意味ですか?

A Privacy Sandbox API in Chrome and Android that lets advertisers measure ad conversions across sites without cross-site identifiers, using browser-mediated, noise-injected event-level or aggregated reports.

Attribution Reporting API はどのように機能しますか?

The Attribution Reporting API (ARA) is the Privacy Sandbox mechanism for measuring ad-driven conversions without exposing cross-site identifiers. Sources (ad clicks or views) are registered on the publisher side; triggers (conversions) are registered on the advertiser side. The browser maintains the join between them locally and, at delayed and randomized intervals, sends one of two kinds of report. Event-level reports return a noisy, low-resolution mapping from a source event to a conversion event, suitable for click attribution. Aggregatable reports go through a separate Aggregation Service running in a trusted execution environment, which adds calibrated noise (differential privacy) before returning aggregate dashboards across many users. Both report types are designed to bound the cross-site information any caller can learn. ARA is one of the central pieces of the post-third-party-cookie measurement story and a focus of regulator attention (CMA, French CNIL, German DPAs). For ad-tech and measurement vendors, integrating ARA requires substantial backend changes for noise budgets, report aggregation, and trust-establishment with the Aggregation Service.

Attribution Reporting API からどのように防御しますか?

Attribution Reporting API に対する防御は通常、上記の定義で述べたとおり、技術的統制と運用上の実践を組み合わせます。

Attribution Reporting API の別名は何ですか?

一般的な別名: ARA, Attribution Reporting。

● 関連用語