Anomaly Detection with LWE Encrypted Control

Fuente: arXiv
Saved in:
Bibliographic Details
Main Authors: Alisic, Rijad, Kim, Junsoo, Sandberg, Henrik
Format: Preprint
Published: 2025
Subjects:
Online Access:
Tags: Add Tag
No Tags, Be the first to tag this record!
_version_ 1866929715538821120
author Alisic, Rijad
Kim, Junsoo
Sandberg, Henrik
author_facet Alisic, Rijad
Kim, Junsoo
Sandberg, Henrik
contents Detecting attacks using encrypted signals is challenging since encryption hides its information content. We present a novel mechanism for anomaly detection over Learning with Errors (LWE) encrypted signals without using decryption, secure channels, nor complex communication schemes. Instead, the detector exploits the homomorphic property of LWE encryption to perform hypothesis tests on transformations of the encrypted samples. The specific transformations are determined by solutions to a hard lattice-based minimization problem. While the test's sensitivity deteriorates with suboptimal solutions, similar to the exponential deterioration of the (related) test that breaks the cryptosystem, we show that the deterioration is polynomial for our test. This rate gap can be exploited to pick parameters that lead to somewhat weaker encryption but large gains in detection capability. Finally, we conclude the paper by presenting a numerical example that simulates anomaly detection, demonstrating the effectiveness of our method in identifying attacks.
format Preprint
id arxiv_https___arxiv_org_abs_2502_10283
institution arXiv
publishDate 2025
record_format arxiv
spellingShingle Anomaly Detection with LWE Encrypted Control
Alisic, Rijad
Kim, Junsoo
Sandberg, Henrik
Cryptography and Security
Systems and Control
Detecting attacks using encrypted signals is challenging since encryption hides its information content. We present a novel mechanism for anomaly detection over Learning with Errors (LWE) encrypted signals without using decryption, secure channels, nor complex communication schemes. Instead, the detector exploits the homomorphic property of LWE encryption to perform hypothesis tests on transformations of the encrypted samples. The specific transformations are determined by solutions to a hard lattice-based minimization problem. While the test's sensitivity deteriorates with suboptimal solutions, similar to the exponential deterioration of the (related) test that breaks the cryptosystem, we show that the deterioration is polynomial for our test. This rate gap can be exploited to pick parameters that lead to somewhat weaker encryption but large gains in detection capability. Finally, we conclude the paper by presenting a numerical example that simulates anomaly detection, demonstrating the effectiveness of our method in identifying attacks.
title Anomaly Detection with LWE Encrypted Control
topic Cryptography and Security
Systems and Control
url https://arxiv.org/abs/2502.10283