Personal Data Protection Act Article 12

When a government or non-government agency becomes aware that the personal data it holds has been stolen, altered, damaged, lost, or leaked, it shall notify the data subject.Where the circumstances described under the preceding paragraph fall within a specified scope of report, the government or non-government agency shall submit reports to the following authorities:1.Government agencies shall submit reports to the competent authority and the authorities designated under Paragraph 1, Article 21-1 to receive reports on their implementation status.2.Non-government agencies shall submit reports to the competent authority. Upon receiving the reports, the competent authority shall also inform the authorities in charge of the industries concerned.Under the circumstances described under Paragraph 1, the government or non-government agency shall take immediate and effective countermeasures to prevent the incident from escalating, document the relevant facts, impacts, and response measures taken, and preserve the relevant records for inspection by the competent authority.The regulations on the content, method, time limit, and scope of notification or reporting, countermeasures, record retention, and other relevant matters under the preceding three paragraphs shall be prescribed by the competent authority.
中文原文 個人資料保護法第12條
公務機關或非公務機關知悉所保有之個人資料被竊取、竄改、毀損、滅失或洩漏時,應通知當事人。
前項情形符合一定通報範圍者,公務機關或非公務機關應通報下列機關:
一、公務機關:向主管機關及依第二十一條之一第一項規定收受其實施情形之機關通報。
二、非公務機關:向主管機關通報。
主管機關受理通報後,並轉知其目的事業主管機關。
第一項情形,公務機關或非公務機關應採取即時有效之應變措施,防止事故之擴大,及記載相關事實、影響、已採取之因應措施,並保存相關紀錄,以備主管機關查驗。
前三項應通知或通報之內容、方式、時限與通報範圍、應變措施、紀錄保存及其他相關事項之辦法,由主管機關定之。

English translation for reference only; the Chinese text prevails. Not legal advice.