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1.
Time-division multiple access (TDMA) and code-division multiple access (CDMA) are two technologies used in digital cellular networks. The authentication protocols of TDMA networks have been proven to be vulnerable to side-channel analysis (SCA), giving rise to a series of powerful SCA-based attacks against unprotected subscriber identity module (SIM) cards. CDMA networks have two authentication protocols, cellular authentication and voice encryption (CAVE) based authentication protocol and authentication and key agreement (AKA) based authentication protocol, which are used in different phases of the networks. However, there has been no SCA attack for these two protocols so far. In this paper, in order to figure out if the authentication protocols of CDMA networks are sufficiently secure against SCA, we investigate the two existing protocols and their cryptographic algorithms. We find the side-channel weaknesses of the two protocols when they are implemented on embedded systems. Based on these weaknesses, we propose specific attack strategies to recover their authentication keys for the two protocols, respectively. We verify our strategies on an 8-bit microcontroller and a real-world SIM card, showing that the authentication keys can be fully recovered within a few minutes with a limited number of power measurements. The successful experiments demonstrate the correctness and the effectiveness of our proposed strategies and prove that the unprotected implementations of the authentication protocols of CDMA networks cannot resist SCA.  相似文献   
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A CAVE-like environment as a tool for full-size train design   总被引:1,自引:1,他引:0  
Simulations of models, in all different areas, is an expanding, attractive line of work. More and more applications are taking advantage of the improvements in technology and knowledge in this field, thus achieving results that would have been impossible to achieve with a real model, or foreseeing facts that otherwise would have been encountered too late in the production process. The rail industry is one possible beneficiary of this approach. Usually, before commencing the fabrication process of a new train, the construction of a full-size model is mandatory. Instead of building this full-size real model, which leaves little room for later, last-minute modifications, a virtual model can be built in the digital realm, thus offering a new platform for easier interaction with it. In this article, a simulation of a train is presented in order to tackle visual, aesthetic and ergonomic issues. The simulation runs on a PC-based CAVE-like architecture, offering a certain degree of interaction to the user, and combines static and dynamic computer-generated imagery, both with and without stereoscopy for 3D visualisation, as well as augmented virtuality techniques for the integration of the train with its environment.  相似文献   
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研究了CDMA2000 1x空中接口加密机制的原理和过程,完成了空中接口部分信患加密的软件实现,在测试的基础上分析了加密机制的安全性,并指出了其中存在的安全漏洞。  相似文献   
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沉浸式三维虚拟漫游技术研究   总被引:4,自引:0,他引:4  
虚拟现实技术作为一门新兴的综合性信息技术,其在很多领域都发挥着不可或缺的作用。其中CAVE沉浸式虚拟系统,可以应用于任何具有沉浸感需求的虚拟仿真应用领域。针对CAVE系统研究并实现了在虚拟场景中的漫游交互,结合Multigen Creator和3DMAX来创建逼真的虚拟城镇场景,使用Vega建立漫游时所需的对象及其关联,然后通过无线手柄在该场景内实时漫游交互,最终实现了一个有三面投影面的CAVE沉浸式虚拟环境,并且可以在系统中进行实时的漫游交互,使用户有一种身临其境之感。  相似文献   
6.
Virtual reality (VR) has been used both to simulate situations that are too dangerous to practice in real life and as a tool to help children learn. This study was conducted as part of a larger more comprehensive long-term research project which aims to combine the two techniques and demonstrate a novel application of the result, using immersive VR to help children learn about fire hazards and practice escape techniques. In the current study, a CAVE was used to immerse participants in a fire scene. To improve the children’s motivation for learning over prior VR fire-safety training methods, game-like interface interaction techniques were used and students were encouraged to explore the virtual world. Rather than being passive viewers, as in prior related studies, the children were given full control to navigate through the virtual environment and to interact with virtual objects using a game pad and a 6DOF wand. Students identified home fire hazards with a partner and then practiced escaping from a simulated fire in the virtual environment. To test for improved motivation, a user study was completed. Results indicate that students were more engaged by the new game-like learning environment and that they reported that they found the experience fun and intriguing. Their enhanced enthusiasm for what is relatively standard fire-safety information demonstrates the promise of using game-based virtual environments for vital but otherwise tedious fire-safety skills training for children.  相似文献   
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由于使用无线传输和网络的开放性,移动通信面临着很多安全威胁。该文重点研究CDMA系统空中接口的安全机制,详细分析了针对主动攻击的鉴权机制的原理和过程,以及被动攻击的加密机制,其中重点介绍了一种数据加密技术——混合密码体制。  相似文献   
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虚拟现实中的视觉系统与其实现技术   总被引:4,自引:2,他引:2  
视觉系统是实现虚拟现实的关键部分。本文探讨了虚拟环境中视觉系统的设计思想,并介绍了现时流行的虚拟环境中视觉系统的实现方案。  相似文献   
9.
重型筑路机械的虚拟设计与制造技术可以减少设计过程中的错误、缩短开发周期。本文介绍了一种满足ISO6 6 82规范的工程机械可调节驾驶模拟平台的设计 ,将该模拟驾驶平台放到 CAVE中 ,与虚拟图形系统、输入输出系统组成虚拟驾驶系统。通过虚拟驾驶系统来对重型筑路机械的设计进行评价 ,如方向盘、油门、刹车踏板和其它操纵机构的设计是否满足人机工程的要求。在该平台的设计中我们使用了连杆机构 ,可使方向盘、操纵杆等在一定区域内非常方便地调节 ,这样不同类型的重型筑路机械均可使用该平台来组成虚拟驾驶系统。我们设计了专门的程序来对四杆机构的运动进行仿真 ,以便选择正确的连杆尺寸。最后 ,文章介绍了动感椅的集成。  相似文献   
10.
To specify the region of interest (ROI) is an effective approach to visualize large scale simulation data. We have developed a three-dimensional visualization software with ROI function for the CAVE virtual reality systems. This software enables the user to perform fully three-dimensional and interactive visualization of large scale computational fluid dynamics (CFD) data. The user specifies a ROI in the CAVE room by a three-dimensional “mouse-drag”. The data in the specified ROI is automatically extracted from the original CFD data. This ROI procedure can be repeated recursively. The resolution in each ROI is kept approximately constant. A data set of three vector fields and eight scalar fields whose size is about 1 GB each was successfully analyzed.  相似文献   
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