arXiv subjects

Hongzhi Liu

Publications and source records attributed to Hongzhi Liu.

22 records · Page 2Linked to original sources

arXiv2019

EncryptGAN: Image Steganography with Domain Transform

We propose an image steganographic algorithm called EncryptGAN, which disguises private image communication in an open communication channel. The insight is that content transform between two very different domains (e.g., face to flower) allows one to hide image messages in one domain (face) and communicate using its counterpart in another domain (flower). The key ingredient in our method, unlike related approaches, is a specially trained network to extract transformed images from both domains and use them as the public and private keys. We ensure the image communication remain secret except for the intended recipient even when the content transformation networks are exposed. To communicate, one directly pastes the `message' image onto a larger public key image (face). Depending on the location and content of the message image, the `disguise' image (flower) alters its appearance and shape while maintaining its overall objectiveness (flower). The recipient decodes the alternated image to uncover the original image message using its message image key. We implement the entire procedure as a constrained Cycle-GAN, where the public and the private key generating network is used as an additional constraint to the cycle consistency. Comprehensive experimental results show our EncryptGAN outperforms the state-of-arts in terms of both encryption and security measures.

cs.MM↗

arXiv2017

Android Multi-Level System Permission Management Approach

With the expansion of the market share occupied by the Android platform, security issues (especially application security) have become attention focus of researchers. In fact, the existing methods lack the capabilities to manage application permissions without root privilege. This study proposes a dynamic management mechanism of Android application permissions based on security policies. The paper first describes the permissions by security policies, then implementes permission checking code and request evaluation algorithm in Android framework layer. Experimental results indicate that the presented approach succeeds in permission management of Android applications, and its system overhead is low, which makes it an effective method for Android permission management.

cs.CR↗

arXiv2016

Two minimal unique ergodic diffeomorphisms on a manifolds and their smooth crossed product algebras

In this article we construct two minimal unique ergodic diffeomorphisms $α$ and $β$ on $S^3 \times S^{6} \times S^{8} $. We will show that $C(S^3 \times S^{6} \times S^{8}) \rtimes_α\mathbb{Z} $ and $C(S^3 \times S^{6} \times S^{8})\rtimes_β\mathbb{Z} $ are equivalent to each other, while $C^\infty (S^3 \times S^{6} \times S^{8})\rtimes_α\mathbb{Z} $ and $C^\infty(S^3 \times S^{6} \times S^{8} )\rtimes_β\mathbb{Z} $ are not.

math.OA↗

arXiv2016

Smooth crossed products induced by minimal unique ergodic diffeomorphisms on odd spheres

For minimal unique ergodic diffeomorphisms $α_n$ of $S^{2n+1} (n>0)$ and $α_m$ of $S^{2m+1}(m>0)$, the $C^*$-crossed product algebra $C(S^{2n+1})\rtimes_{α_n} \mathbb{Z}$ is isomorphic to $C(S^{2m+1})\rtimes_{α_m} \mathbb{Z}$ even though $n\neq m$ . However, by cyclic cohomology, we show that smooth crossed product algebra $C^\infty(S^{2n+1})\rtimes_{α_n} \mathbb{Z}$ is not isomorphic to $C^\infty(S^{2m+1})\rtimes_{α_m} \mathbb{Z}$ if $n\neq m$.

math.OA↗