一种基于通道的AVISPA扩展方法研究

针对AVISPA工具在分析某些消息需要依靠具有特定属性的信道传递的安全协议或服务中存在的问题, 提出了一种基于抽象通道的扩展方法。抽象通道具有相关的安全性质保证如认证性, 能够对提供安全性质保证的底层服务建模, 并基于密码机制和标签等实现了抽象通道。利用扩展后的AVISPA工具分析有无消息源认证机制的Diffie-Hellman密钥交换协议的安全性, 表明了方法的有效性, 并且能够简化协议建模过程和增强AVISPA工具协议描述分析能力。     

一种基于（部分）广播通道的秘密共享方案

在传统的秘密共享方案中,秘密分发者通过秘密通道分发秘密份额给一组参与者.结合Rei方案和Amos方案,提出仅需一个秘密通道的秘密共享方案.在该方案的秘密分发阶段,秘密分发者与参与者之间使用部分广播通道进行通信,秘密分发者与秘密合并者之间使用一个秘密通道进行通信;在秘密重构阶段,参与者与秘密合并者之间使用广播通道进行通信.通过对该方案进行分析可知,该方案的通道数和总的通信量比已知的两个方案具有明显的优势.     

光纤通道──连接未来网络和通道的桥梁

从结构、协议和应用方面对光纤通道作了较为全面的介绍。     

IP多点广播技术及应用

ＩＰ多点广播是一种新兴技术,它以传统的ＴＣＰ／ＩＰ网络为载体,具有一对多和多对多的数据交付能力,为网络实时多嫖体和批量数据传输提供了解决手段,该６文简要介绍了ＩＰ多点广播技术的产生、发展和应用,重点分析了它的工作机制,包括多点广播的地址构造,Ｉｎｔｅｒｎｅｔ组管理协议和路由技术。     

基于IP的扩展USB总线iUSB的设计

为在IP网络上共享USB接口的外围设备,提出了基于IP的扩展USB总线iUSB的概念,并且通过在客户端的USB驱动层中加入虚拟主控制器接口（VHCI）和在服务器端的USB驱动层中加入虚拟设备驱动（VDD）来实现iUSB.由于包括了一个与操作系统无关的协议iUSB,使得网络上的USB设备可以跨平台、透明地被访问,这是iUSB的主要优点.另外,这种实现在驱动级的方法,与传统的远程过程调用共享设备的方法相比,提供了更多的设备和控制信息,减轻了服务器端的负担,且具有更好的安全性.     

基于部分广播通道的可验证秘密共享方案

借鉴Amos方案中重构秘密的思想对Rei方案进行了完善,提出一种基于部分广播通道的可验证秘密共享方案.在该方案的秘密分发阶段,秘密分发者与参与者之间使用部分广播通道进行通信,秘密重构阶段使用广播通道进行通信.该方案可处理不诚实秘密分发者与参与者情况,具有可验证性.通过对该方案的分析可知,该方案的通道数和总的通信量比已知的两个方案具有明显的优势.此外,该方案中各参与者的秘密份额可反复使用.     

IP多路广播协议及应用

本文介绍ＩＰ多路广播（ＩＰＭｕｌｔｉｃａｓｔ）协议的产生、发展以及多路广播的应用模型和最为典型的应用ＭＢｏｎｅ     

构件行为协议实时性扩展及相容性验证

对复杂实时构件系统行为进行形式化描述和相容性验证,可以有效提高系统的正确性、可靠性。分析了学术界和工业界的主流构件模型及常见时间行为的形式化描述方法,对构件行为协议BP(Behavior Protocol)进行了扩展,提出了时间行为协议TbP(Timed Behavior Protocol),分析了构件组合中常见的相容性错误类型,给出了基于时间行为协议的构件组合相容性验证算法。TBP应用简洁、方便、易于验证。结合具体例子给出了应用示例。     

网络隐通道的处理方式

本文首先介绍了网络隐通道的概念,讨论了在网络通信中隐通道存在的技术基础和实现原理,对基于网络通信协议的隐通道技术进行了深入分析。在此基础上讨论了隐通道技术的发展趋势并从网络安全的角度给出了对网络通信中隐通道的防范措施。     

应用三层交换和VLAN技术建立Intranet安全通道

通过对交换技术以及VLAN(虚拟局域网)技术原理的研究,对企业现存网络运行中存在的问题和潜在的安全隐患做出了一定的分析,利用三层交换技术和VLAN技术的结合对企业网络进行了网段的逻辑微划分,从而提出了建设企业内联网络安全通道的方案,并通过实践论证了这一方案的可行性。     

Channel dynamic adjustment in data broadcast

Data broadcasting has become the preferred method to dispense data to a large number of mobile users. Current researches on on-demand data broadcast mainly propose algorithms based on a single broadcast channel or fixed multi-channel, i.e., fixed channel model. As a result of the dynamic diversity of data characteristics and client demands, the fixed channel model faces significant challenges in parallel broadcast diverse data. Further, the dynamic adjustment of the broadcast channel (dynamic channel model) based on client requests is favorable to service quality because it determines the number and sizes of channels that adapt to client demand in real-time. However, the dynamic channel model has not yet been thoroughly investigated for on-demand wireless data broadcasts. Accordingly, in this paper, a channel dynamic adjustment method (CDAM) is proposed. The innovations behind CDAM lie in three aspects. First, a data item priority evaluation and selection algorithm (S-RxW/SL) is proposed for evaluating the priority of data items and selecting the high priority data items to be considered in a broadcast cycle. Second, a weight and size average cluster algorithm (WSAC) is proposed for mining data item characteristics and clustering them. Third, based on the clustering results of WSAC, a channel splitting and data allocation algorithm (CSDA) is proposed for dynamically splitting the channel and allocating data items to the corresponding sub-channel. We compare the proposed method with some state-of-the-art scheduling methods through simulation. The theoretical findings and simulation results reveal that significantly better request loss rate (LR) can be obtained by using our method as compared to its alternatives.     

Leakage-based user scheduling in MU-MIMO broadcast channel

This paper investigates user scheduling in multi-user MIMO broadcast channel. We propose a leakagebased user scheduling scheme, in which a user’s leakage power to other users is an important factor to determine whether the user should be selected. The accuracy of closed-form solution of SLNR (signal to leakage plus noise ratio) makes the proposed scheme outperform the traditional scheduling method based on SINR (signal to interference plus noise ratio). The proposed algorithms can work in case of perfect or limited feedback of CSI (channel state information) at transmitter, and the advantage is verified with numerical results. A tradeoff relation among feedback bits number, active user number and transmit/receive antennas number is analyzed, which serves as a system design guideline.     

An extended dominating node approach to broadcast and globalcombine in multiport wormhole-routed mesh networks

A new approach to the design of collective communication operations in wormhole-routed mesh networks is described. The approach extends the concept of dominating sets in graph theory by accounting for the relative distance-insensitivity of the wormhole switching strategy and by taking advantage of a multiport communication architecture, which allows each node to simultaneously transmit messages on different outgoing channels. Collective communication operations are defined in terms of sets of extended dominating nodes (EDNs). The nodes in a set of EDNs can deliver (receive) messages to (from) a different, larger set of nodes in a single message-passing step under dimension-ordered wormhole routing and without channel contention among messages. The EDN model can be applied to different collective operations in 2D and 3D mesh networks. The authors focus on EDN-based broadcast and global combine operations. Performance evaluation results are presented that confirm the advantage of this approach over other methods     

Interference-aware multicast and broadcast routing in wireless mesh networks using both rate and channel diversity

This paper deals with the problem of load-balanced routing in multi-radio multi-rate multi-channel wireless mesh networks. Our analysis relies on the multicast and broadcast sessions, where each session has a specific bandwidth requirement. We show that using both rate and channel diversity significantly improves the network performance. Toward this goal, we propose two cross-layer algorithms named the “Interference- and Rate-aware Multicast Tree (IRMT)” and the “Interference- and Rate-aware Broadcast Tree (IRBT)”. The proposed algorithms jointly address the problems of routing tree construction, transmission channel selection, transmission rate selection, and call admission control. As an advantage, the IRMT and the IRBT algorithms consider both inter-flow and intra-flow interference. These schemes not only improve the utilization of the network resources, but also balance the traffic load over the network. Numerical results demonstrate the efficiency of the proposed algorithms in terms of the number of transmissions, the load-balancing, and the network throughput.     

A hybrid scheduling scheme for data broadcast over a single channel in mobile environments

Various broadcast schemes have been proposed to reduce the data access time of mobile clients. However, they are based either on the mobile users’ data access frequencies or on the semantic relations of the data. In this paper, we present a hybrid data broadcast scheme based both on semantic relationships and access probabilities. The broadcast scheme we propose generates a broadcast sequence according to the semantic relationships and replicates popular data items several times according to the data access probabilities. The efficiency of our broadcast scheme is shown via performance evaluations.     

Attention-based neural joint source-channel coding of text for point to point and broadcast channel

In this work, we consider the transmissions of structured data such as text over a noisy channel and correlated texts over a broadcast channel. As the separate source-channel coding principle no longer holds in such scenarios, we propose a joint source-channel coding scheme which is based on deep learning architecture. In order to enhance the convergence speed, we adopt the bidirectional gated recurrent unit at the encoder. For the decoder, to improve the recovery quality, we propose the following two types of strategies: (1) After a unidirectional neural network based decoder is used, a generative adversarial network is applied to train the whole joint source-channel coding framework and pointwise mutual information is added to the objective function of beam search process; (2) Rather than using a unidirectional neural network-based decoder, we develop a bidirectional neural network based and bidirectional attention mechanism integrated decoder to utilize past and future information. Experiments under different types of channels show that our schemes are superior to the existing deep learning joint source-channel coding method and in the case of low bit budget, long sentence length and small channel signal to noise ratio, our models are significantly superior to those of separate source-channel coding. In addition, we extend the proposed unidirectional and bidirectional decoders to the broadcast channel. Additionally, to improve the performance of unidirectional decoding, we utilize not only the correlation between adjacent words in the same text but also the correlation between words in different languages with the same meaning in the beam search process.

     

保护信道和排队相结合的信道分配策略

提出了一种适用于语音、数据呼叫的蜂窝移动通信系统的信道分配策略。该策略为数据呼叫提供保护信道,降低数据呼叫的阻塞率。同时,采取语音呼叫排队策略抑制数据保护信道引起的语音呼叫阻塞率的恶化。为了进一步提高系统的性能,在策略中引入了不耐烦顾客,并建立了带有不耐烦顾客的排队模型。仿真结果表明该策略能够有效地降低语音呼叫和数据呼叫阻塞率,改善系统性能。     

Key continual-leakage resilient broadcast cryptosystem from dual system in broadcast networks

In order to tolerate possible leakage of secret keys, leakage-resilient cryptosystem models a class of attractive leakage output by allowing an adversary to provide any computable leakage function and learning the partial keys or other possible intemal states from the output of function. In this work, we present an adaptively secure broadcast encryption resilient to key continual leakage in the standard model. Our scheme provides the tolerance of continual leakage, in which any user can generate multiple private keys per user by periodically updating the key. We use the dual system encryption mechanism to implement the leakage resilience and adaptive security, and intrinsically set an algorithm to refresh a key and produce a same distributed new key. We also give the evaluation of the leakage bound and leakage fraction, and the simulations show that our scheme can tolerate about 71% leakage fraction with 3.34× 10^-52 failure probability in standard 80-bit security level when we adjust the leakage factor to allow the private key to be 100 Kb.     

Key continual-leakage resilient broadcast cryptosystem from dual system in broadcast networks

In order to tolerate possible leakage of secret keys, leakage-resilient cryptosystem models a class of attractive leakage output by allowing an adversary to provide any computable leakage function and learning the partial keys or other possible internal states from the output of function. In this work, we present an adaptively secure broadcast encryption resilient to key continual leakage in the standard model. Our scheme provides the tolerance of continual leakage, in which any user can generate multiple private keys per user by periodically updating the key. We use the dual system encryption mechanism to implement the leakage resilience and adaptive security, and intrinsically set an algorithm to refresh a key and produce a same distributed new key. We also give the evaluation of the leakage bound and leakage fraction, and the simulations show that our scheme can tolerate about 71% leakage fraction with 3.34 × 10^-52 failure probability in standard 80-bit security level when we adjust the leakage factor to allow the private key to be 100 Kb.