Saved in:
Bibliographic Details
Main Authors: Feng, Yapei, Jiang, Feng, Wu, Shanhao, Zhong, Hua
Format: Preprint
Published: 2025
Subjects:
Online Access:https://arxiv.org/abs/2510.02332
Tags: Add Tag
No Tags, Be the first to tag this record!
_version_ 1866915531014012928
author Feng, Yapei
Jiang, Feng
Wu, Shanhao
Zhong, Hua
author_facet Feng, Yapei
Jiang, Feng
Wu, Shanhao
Zhong, Hua
contents Neural linguistic steganography aims to embed information into natural text while preserving statistical undetectability. A fundamental challenge in this ffeld stems from tokenization ambiguity in modern tokenizers, which can lead to catastrophic decoding failures. The recent method, SyncPool, addresses this ambiguity by employing a coarse-grained synchronization mechanism over groups of ambiguous candidates. However, SyncPool sacriffces embedding capacity, as it utilizes the entire Shannon entropy of an ambiguous group solely for synchronization rather than for payload embedding. We propose a method named look-ahead Sync, which overcomes the capacity limitation of SyncPool while retaining its provable security guarantees. Our approach performs minimal synchronized sampling only on truly indistinguishable token sequences, while strategically preserving all other discernible paths to maximize embedding capacity. We provide theoretical proofs for the security of our method and analyze the gap between its achievable embedding capacity and the theoretical upper bound. Experiments on English (using Llama 3) and Chinese (using Qwen 2.5) benchmarks show that our method consistently approaches the theoretical capacity upper bound and signiffcantly outperforms SyncPool. The improvement in embedding rate exceeds 160% in English and 25% in Chinese, particularly in settings with larger candidate pools. This work represents a signiffcant step toward practical high-capacity provably secure linguistic steganography.
format Preprint
id arxiv_https___arxiv_org_abs_2510_02332
institution arXiv
publishDate 2025
record_format arxiv
spellingShingle A High-Capacity and Secure Disambiguation Algorithm for Neural Linguistic Steganography
Feng, Yapei
Jiang, Feng
Wu, Shanhao
Zhong, Hua
Computation and Language
Artificial Intelligence
Cryptography and Security
Neural linguistic steganography aims to embed information into natural text while preserving statistical undetectability. A fundamental challenge in this ffeld stems from tokenization ambiguity in modern tokenizers, which can lead to catastrophic decoding failures. The recent method, SyncPool, addresses this ambiguity by employing a coarse-grained synchronization mechanism over groups of ambiguous candidates. However, SyncPool sacriffces embedding capacity, as it utilizes the entire Shannon entropy of an ambiguous group solely for synchronization rather than for payload embedding. We propose a method named look-ahead Sync, which overcomes the capacity limitation of SyncPool while retaining its provable security guarantees. Our approach performs minimal synchronized sampling only on truly indistinguishable token sequences, while strategically preserving all other discernible paths to maximize embedding capacity. We provide theoretical proofs for the security of our method and analyze the gap between its achievable embedding capacity and the theoretical upper bound. Experiments on English (using Llama 3) and Chinese (using Qwen 2.5) benchmarks show that our method consistently approaches the theoretical capacity upper bound and signiffcantly outperforms SyncPool. The improvement in embedding rate exceeds 160% in English and 25% in Chinese, particularly in settings with larger candidate pools. This work represents a signiffcant step toward practical high-capacity provably secure linguistic steganography.
title A High-Capacity and Secure Disambiguation Algorithm for Neural Linguistic Steganography
topic Computation and Language
Artificial Intelligence
Cryptography and Security
url https://arxiv.org/abs/2510.02332