Context-Fidelity Boosting: Enhancing Faithful Generation through Watermark-Inspired Decoding

Fuente: arXiv
Saved in:
Bibliographic Details
Main Authors: Zhang, Weixu, Ye, Fanghua, Gao, Qiang, Li, Jian, Wu, Haolun, Tian, Yuxing, Duan, Sijing, Du, Nan, Li, Xiaolong, Liu, Xue
Format: Preprint
Published: 2026
Subjects:
Online Access:
Tags: Add Tag
No Tags, Be the first to tag this record!
_version_ 1866910162297552896
author Zhang, Weixu
Ye, Fanghua
Gao, Qiang
Li, Jian
Wu, Haolun
Tian, Yuxing
Duan, Sijing
Du, Nan
Li, Xiaolong
Liu, Xue
author_facet Zhang, Weixu
Ye, Fanghua
Gao, Qiang
Li, Jian
Wu, Haolun
Tian, Yuxing
Duan, Sijing
Du, Nan
Li, Xiaolong
Liu, Xue
contents Large language models (LLMs) often produce content that contradicts or overlooks information provided in the input context, a phenomenon known as faithfulness hallucination. In this paper, we propose Context-Fidelity Boosting (CFB), a lightweight and general decoding-time framework that reduces such hallucinations by increasing the generation probability of source-supported tokens. Motivated by logit-shaping principles from watermarking techniques, CFB applies additive token-level logit adjustments based on a token's degree of support from the input context. Specifically, we develop three boosting strategies: static boosting, which applies a fixed bias to source-supported tokens; context-aware boosting, which scales this bias using the divergence between next-token distributions with and without context; and token-aware boosting, which further redistributes the adaptive bias according to local relevance estimated from source-position attention and source-scoped semantic similarity. CFB requires no retraining or architectural changes, making it compatible with a wide range of LLMs. Experiments on summarization and question answering tasks across multiple open-source LLMs show that CFB consistently improves faithfulness metrics with minimal generation overhead. Our implementation is fully open-sourced.
format Preprint
id arxiv_https___arxiv_org_abs_2604_22335
institution arXiv
publishDate 2026
record_format arxiv
spellingShingle Context-Fidelity Boosting: Enhancing Faithful Generation through Watermark-Inspired Decoding
Zhang, Weixu
Ye, Fanghua
Gao, Qiang
Li, Jian
Wu, Haolun
Tian, Yuxing
Duan, Sijing
Du, Nan
Li, Xiaolong
Liu, Xue
Computation and Language
Large language models (LLMs) often produce content that contradicts or overlooks information provided in the input context, a phenomenon known as faithfulness hallucination. In this paper, we propose Context-Fidelity Boosting (CFB), a lightweight and general decoding-time framework that reduces such hallucinations by increasing the generation probability of source-supported tokens. Motivated by logit-shaping principles from watermarking techniques, CFB applies additive token-level logit adjustments based on a token's degree of support from the input context. Specifically, we develop three boosting strategies: static boosting, which applies a fixed bias to source-supported tokens; context-aware boosting, which scales this bias using the divergence between next-token distributions with and without context; and token-aware boosting, which further redistributes the adaptive bias according to local relevance estimated from source-position attention and source-scoped semantic similarity. CFB requires no retraining or architectural changes, making it compatible with a wide range of LLMs. Experiments on summarization and question answering tasks across multiple open-source LLMs show that CFB consistently improves faithfulness metrics with minimal generation overhead. Our implementation is fully open-sourced.
title Context-Fidelity Boosting: Enhancing Faithful Generation through Watermark-Inspired Decoding
topic Computation and Language
url https://arxiv.org/abs/2604.22335