Differentially-Private Text Rewriting reshapes Linguistic Style

Stefan Arnold


Abstract
Differential Privacy (DP) for text matured from disjointed word-level substitutions to contiguous sentence-level rewriting by leveraging the generative capacity of language models. While this form of text privatization is best suited for balancing formal privacy guarantees with grammatical coherence, its impact on the register identity of text remains largely unexplored. By conducting a multidimensional stylistic profiling of differentially-private rewriting, we demonstrate that the cost of privacy extends far beyond lexical variation. Specifically, we find that rewriting under privacy constraints induces a systematic functional mutation of the text’s communicative signature. This shift is characterized by the severe attrition of interactive markers, contextual references, and complex subordination. By comparing autoregressive paraphrasing against bidirectional substitution across a spectrum of privacy budgets, we observe that both architectures force convergence toward a non-involved and non-persuasive register. This register-blind sanitization effectively preserves semantic content but structurally homogenizes the nuanced stylistic markers that define human-authored discourse.
Anthology ID:
2026.privatenlp-main.7
Volume:
Proceedings of the Seventh Workshop on Privacy in Natural Language Processing
Month:
July
Year:
2026
Address:
San Diego, California
Editors:
Ivan Habernal, Sepideh Ghanavati, Sara Haghighi, Krithika Ramesh, Timour Igamberdiev, Shomir Wilson
Venues:
PrivateNLP | WS
SIG:
Publisher:
Association for Computational Linguistics
Note:
Pages:
96–106
Language:
URL:
https://preview.aclanthology.org/ingest-acl-workshops/2026.privatenlp-main.7/
DOI:
Bibkey:
Cite (ACL):
Stefan Arnold. 2026. Differentially-Private Text Rewriting reshapes Linguistic Style. In Proceedings of the Seventh Workshop on Privacy in Natural Language Processing, pages 96–106, San Diego, California. Association for Computational Linguistics.
Cite (Informal):
Differentially-Private Text Rewriting reshapes Linguistic Style (Arnold, PrivateNLP 2026)
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PDF:
https://preview.aclanthology.org/ingest-acl-workshops/2026.privatenlp-main.7.pdf