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Bibliographic Details
Main Authors: Charpentier, Lucas Georges Gabriel, Lison, Pierre
Format: Preprint
Published: 2025
Subjects:
Online Access:https://arxiv.org/abs/2505.12859
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author Charpentier, Lucas Georges Gabriel
Lison, Pierre
author_facet Charpentier, Lucas Georges Gabriel
Lison, Pierre
contents Documents revealing sensitive information about individuals must typically be de-identified. This de-identification is often done by masking all mentions of personally identifiable information (PII), thereby making it more difficult to uncover the identity of the person(s) in question. To investigate the robustness of de-identification methods, we present a novel, RAG-inspired approach that attempts the reverse process of re-identification based on a database of documents representing background knowledge. Given a text in which personal identifiers have been masked, the re-identification proceeds in two steps. A retriever first selects from the background knowledge passages deemed relevant for the re-identification. Those passages are then provided to an infilling model which seeks to infer the original content of each text span. This process is repeated until all masked spans are replaced. We evaluate the re-identification on three datasets (Wikipedia biographies, court rulings and clinical notes). Results show that (1) as many as 80% of de-identified text spans can be successfully recovered and (2) the re-identification accuracy increases along with the level of background knowledge.
format Preprint
id arxiv_https___arxiv_org_abs_2505_12859
institution arXiv
publishDate 2025
record_format arxiv
spellingShingle Re-identification of De-identified Documents with Autoregressive Infilling
Charpentier, Lucas Georges Gabriel
Lison, Pierre
Computation and Language
Documents revealing sensitive information about individuals must typically be de-identified. This de-identification is often done by masking all mentions of personally identifiable information (PII), thereby making it more difficult to uncover the identity of the person(s) in question. To investigate the robustness of de-identification methods, we present a novel, RAG-inspired approach that attempts the reverse process of re-identification based on a database of documents representing background knowledge. Given a text in which personal identifiers have been masked, the re-identification proceeds in two steps. A retriever first selects from the background knowledge passages deemed relevant for the re-identification. Those passages are then provided to an infilling model which seeks to infer the original content of each text span. This process is repeated until all masked spans are replaced. We evaluate the re-identification on three datasets (Wikipedia biographies, court rulings and clinical notes). Results show that (1) as many as 80% of de-identified text spans can be successfully recovered and (2) the re-identification accuracy increases along with the level of background knowledge.
title Re-identification of De-identified Documents with Autoregressive Infilling
topic Computation and Language
url https://arxiv.org/abs/2505.12859