Search arXiv⌕ Search
Home/Archive/arXiv

arXiv · 2610.18262

Encrypted Skills Can Become New Security Exploits If AI Agents Know How to Decipher

Yan-Lun Chen·Pin-Yu Chen·Chia-Mu Yu
View original source ↗Read source document ↗Export metadata ↓

Abstract

Third-party skills can expose LLM agents to malicious instructions hidden by encoding. We introduce Ciphered Skill Injection (CSI), which embeds such instructions in skill files for agents to decode and follow. We evaluate Caesar and layered variants across eight models and 139 injection-task pairs, separating instruction recovery from attack success. In the primary setting with shortened skills, the variants achieve attack success rates of up to 47.5% and 40.3%, respectively. Successful decoding does not guarantee attack success, and layering has model-dependent effects. The tested skill scanners rarely flag injected skills. These findings highlight the risk of promoting decoded, untrusted content into actionable instructions.

Explore related subjects

cs.CRcs.AIcs.CL

Keep this discovery

Explore connections, maps & timelines

BibTeXRIS

Yan-Lun Chen, Pin-Yu Chen, Chia-Mu Yu. 2026-10-13. Encrypted Skills Can Become New Security Exploits If AI Agents Know How to Decipher. https://arxiv.org/abs/2610.18262

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related papers

arXiv2026

Simulation-Secure Functional Encryption in the Bounded Storage Model

Functional encryption (FE) is a versatile paradigm that enables fine-grained access control over encrypted data. Despite its potential, achieving the gold standard of simulation-based security for FE is impossible in full generality. Known impossibility results demonstrate that simulation security cannot be attained if an adversary in the security experiment is permitted either an unbounded number of functional key queries or an unbounded number of challenge ciphertexts. In this work, we circumvent these fundamental barriers by considering two distinct memory-restricted settings: the Bounded Quantum Storage Model and the Bounded Classical Storage Model. In these settings, the plain model impossibility results no longer apply, allowing us to obtain new positive results. Specifically, we construct two adaptively simulation-secure FE schemes in the Bounded Quantum Storage Model: 1) Many functional key scheme: A construction supporting many functional key queries and a single challenge ciphertext, assuming only the existence of one-way functions. 2) Many ciphertext scheme: An information-theoretic secure construction supporting a single non-adaptive functional key, many challenge ciphertexts, and many adaptive functional key queries. Furthermore, we demonstrate that both schemes can be ported to the Bounded Classical Storage Model, assuming the existence of disappearing grey-box obfuscation.

cs.CR↗
arXiv2026

Watermarking Continuous Tabular Data Generation

In this paper, we introduce a simple yet effective tabular data watermarking mechanism with statistical guarantees. We show theoretically that the proposed watermark can be effectively detected, while faithfully preserving the data fidelity, and also demonstrates appealing robustness against additive noise attack. The general idea is to achieve the watermarking through a strategic embedding based on simple data binning. Specifically, it divides the feature's value range into finely segmented intervals and embeds watermarks into selected ``green list" intervals. To detect the watermarks, we develop a principled statistical hypothesis-testing framework with minimal assumptions: it remains valid as long as the underlying data distribution has a continuous density function. The watermarking efficacy is demonstrated through rigorous theoretical analysis and empirical validation, highlighting its utility in enhancing the security of synthetic and real-world datasets.

cs.CR↗
arXiv2026

MIRANDA: short signatures from a leakage-free full-domain-hash scheme

We present $\mathsf{Miranda}$, the first family of full-domain-hash signatures based on matrix codes. This signature scheme fulfils the paradigm of Gentry, Peikert and Vaikuntanathan ($\mathsf{GPV}$), which gives strong security guarantees. Our trapdoor is very simple and generic: if we propose it with matrix codes, it can actually be instantiated in many other ways since it only involves a subcode of a decodable code (or lattice) in a unique decoding regime of parameters. Though $\mathsf{Miranda}$ signing algorithm relies on a decoding task where there is exactly one solution, there are many possible signatures given a message to sign and we ensure that signatures are not leaking information on their underlying trapdoor by means of a very simple procedure involving the drawing of a small number of uniform bits. In particular $\mathsf{Miranda}$ does not use a rejection sampling procedure which makes its implementation a very simple task contrary to other $\mathsf{GPV}$-like signatures schemes such as $\mathsf{Falcon}$ or even $\mathsf{Wave}$. We instantiate $\mathsf{Miranda}$ with the famous family of Gabidulin codes represented as spaces of matrices and we study thoroughly its security (in the EUF-CMA security model). For~$128$ bits of classical security, the signature sizes are as low as~$90$ bytes and the public key sizes are in the order of~$2.6$ megabytes.

cs.CR↗