Anchored Sliding Window: Toward Robust and Imperceptible Linguistic Steganography

Fuente: arXiv
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Main Authors: Yan, Ruiyi, Meng, Shiao, Murawaki, Yugo
Format: Preprint
Published: 2026
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author Yan, Ruiyi
Meng, Shiao
Murawaki, Yugo
author_facet Yan, Ruiyi
Meng, Shiao
Murawaki, Yugo
contents Linguistic steganography based on language models typically assumes that steganographic texts are transmitted without alteration, making them fragile to even minor modifications. While previous work mitigates this fragility by limiting the context window, it significantly compromises text quality. In this paper, we propose the anchored sliding window (ASW) framework to improve imperceptibility and robustness. In addition to the latest tokens, the prompt and a bridge context are anchored within the context window, encouraging the model to compensate for the excluded tokens. We formulate the optimization of the bridge context as a variant of prompt distillation, which we further extend using self-distillation strategies. Experiments show that our ASW significantly and consistently outperforms the baseline method in text quality, imperceptibility, and robustness across diverse settings. The code is available at github.com/ryehr/ASW_steganography.
format Preprint
id arxiv_https___arxiv_org_abs_2604_09066
institution arXiv
publishDate 2026
record_format arxiv
spellingShingle Anchored Sliding Window: Toward Robust and Imperceptible Linguistic Steganography
Yan, Ruiyi
Meng, Shiao
Murawaki, Yugo
Computation and Language
Linguistic steganography based on language models typically assumes that steganographic texts are transmitted without alteration, making them fragile to even minor modifications. While previous work mitigates this fragility by limiting the context window, it significantly compromises text quality. In this paper, we propose the anchored sliding window (ASW) framework to improve imperceptibility and robustness. In addition to the latest tokens, the prompt and a bridge context are anchored within the context window, encouraging the model to compensate for the excluded tokens. We formulate the optimization of the bridge context as a variant of prompt distillation, which we further extend using self-distillation strategies. Experiments show that our ASW significantly and consistently outperforms the baseline method in text quality, imperceptibility, and robustness across diverse settings. The code is available at github.com/ryehr/ASW_steganography.
title Anchored Sliding Window: Toward Robust and Imperceptible Linguistic Steganography
topic Computation and Language
url https://arxiv.org/abs/2604.09066