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2017-06-05
das Dôres, Silvia N., Alves, Luciano, Ruiz, Duncan D., Barros, Rodrigo C..  2016.  A Meta-learning Framework for Algorithm Recommendation in Software Fault Prediction. Proceedings of the 31st Annual ACM Symposium on Applied Computing. :1486–1491.

Software fault prediction is a significant part of software quality assurance and it is commonly used to detect faulty software modules based on software measurement data. Several machine learning based approaches have been proposed for generating predictive models from collected data, although none has become standard given the specificities of each software project. Hence, we believe that recommending the best algorithm for each project is much more important and useful than developing a single algorithm for being used in any project. For achieving that goal, we propose in this paper a novel framework for recommending machine learning algorithms that is capable of automatically identifying the most suitable algorithm according to the software project that is being considered. Our solution, namely SFP-MLF, makes use of the meta-learning paradigm in order to learn the best learner for a particular project. Results show that the SFP-MLF framework provides both the best single algorithm recommendation and also the best ranking recommendation for the software fault prediction problem.

Schordan, Markus, Oppelstrup, Tomas, Jefferson, David, Barnes, Jr., Peter D., Quinlan, Dan.  2016.  Automatic Generation of Reversible C++ Code and Its Performance in a Scalable Kinetic Monte-Carlo Application. Proceedings of the 2016 Annual ACM Conference on SIGSIM Principles of Advanced Discrete Simulation. :111–122.

The fully automatic generation of code that establishes the reversibility of arbitrary C/C++ code has been a target of research and engineering for more than a decade as reverse computation has become a central notion in large scale parallel discrete event simulation (PDES). The simulation models that are implemented for PDES are of increasing complexity and size and require various language features to support abstraction, encapsulation, and composition when building a simulation model. In this paper we focus on parallel simulation models that are written in C++ and present an approach and an evaluation for a fully automatically generated reversible code for a kinetic Monte-Carlo application implemented in C++. Although a significant runtime overhead is introduced with our technique, the assurance that the reverse code is generated automatically and correctly, is an enormous win that allows simulation model developers to write forward event code using the entire C++ language, and have that code automatically transformed into reversible code to enable parallel execution with the Rensselaer's Optimistic Simulation System (ROSS).

Hovsepyan, Aram, Scandariato, Riccardo, Joosen, Wouter.  2016.  Is Newer Always Better?: The Case of Vulnerability Prediction Models Proceedings of the 10th ACM/IEEE International Symposium on Empirical Software Engineering and Measurement. :26:1–26:6.

Finding security vulnerabilities in the source code as early as possible is becoming more and more essential. In this respect, vulnerability prediction models have the potential to help the security assurance activities by identifying code locations that deserve the most attention. In this paper, we investigate whether prediction models behave like milk (i.e., they turn with time) or wine (i.e., the improve with time) when used to predict future vulnerabilities. Our findings indicate that the recall values are largely in favor of predictors based on older versions. However, the better recall comes at the price of much higher file inspection ratio values.

Wang, Yang, Wagner, Stefan.  2016.  Towards Applying a Safety Analysis and Verification Method Based on STPA to Agile Software Development. Proceedings of the International Workshop on Continuous Software Evolution and Delivery. :5–11.

Agile methodologies are becoming widespread in modern software development. However, due to a lack of safety assurance activities, agile methods are criticized for being inadequate for the development of safe software. Safety analysis and safety verification are complementary methods for safety assurance. Yet, both usually rely on traditional, waterfall-like processes. Therefore, it is strongly needed to integrate an appropriate safety analysis approach into agile software development processes driving architecture design and verify the safe design at the code level. This paper presents a novel agile process model "S-Scrum" based on the existing development process "Safe Scrum" and extended by a safety analysis method and a safety verification approach based on STPA (System-Theoretic Process Analysis). The proposed agile development process S-Scrum can be separated into three parts: (1) performing safety-guided design by STPA inside each sprint. (2) Verifying safety requirements at the code level by using model checking. (3) Replacing traditional RAMS (Reliability, Availability, Maintainability, Safety) validation on the final product by STPA safety analysis. We adopt other aspects from the original Safe Scrum. Finally, the feasibility of S-Scrum is illustrated with the example of an airbag system.

Baum, Tobias, Liskin, Olga, Niklas, Kai, Schneider, Kurt.  2016.  Factors Influencing Code Review Processes in Industry. Proceedings of the 2016 24th ACM SIGSOFT International Symposium on Foundations of Software Engineering. :85–96.

Code review is known to be an efficient quality assurance technique. Many software companies today use it, usually with a process similar to the patch review process in open source software development. However, there is still a large fraction of companies performing almost no code reviews at all. And the companies that do code reviews have a lot of variation in the details of their processes. For researchers trying to improve the use of code reviews in industry, it is important to know the reasons for these process variations. We have performed a grounded theory study to clarify process variations and their rationales. The study is based on interviews with software development professionals from 19 companies. These interviews provided insights into the reasons and influencing factors behind the adoption or non-adoption of code reviews as a whole as well as for different process variations. We have condensed these findings into seven hypotheses and a classification of the influencing factors. Our results show the importance of cultural and social issues for review adoption. They trace many process variations to differences in development context and in desired review effects.

Prechelt, Lutz, Schmeisky, Holger, Zieris, Franz.  2016.  Quality Experience: A Grounded Theory of Successful Agile Projects Without Dedicated Testers. Proceedings of the 38th International Conference on Software Engineering. :1017–1027.

Context: While successful conventional software development regularly employs separate testing staff, there are successful agile teams with as well as without separate testers. Question: How does successful agile development work without separate testers? What are advantages and disadvantages? Method: A case study, based on Grounded Theory evaluation of interviews and direct observation of three agile teams; one having separate testers, two without. All teams perform long-term development of parts of e-business web portals. Results: Teams without testers use a quality experience work mode centered around a tight field-use feedback loop, driven by a feeling of responsibility, supported by test automation, resulting in frequent deployments. Conclusion: In the given domain, hand-overs to separate testers appear to hamper the feedback loop more than they contribute to quality, so working without testers is preferred. However, Quality Experience is achievable only with modular architectures and in suitable domains.

Kokaly, Sahar, Salay, Rick, Cassano, Valentin, Maibaum, Tom, Chechik, Marsha.  2016.  A Model Management Approach for Assurance Case Reuse Due to System Evolution. Proceedings of the ACM/IEEE 19th International Conference on Model Driven Engineering Languages and Systems. :196–206.

Evolution in software systems is a necessary activity that occurs due to fixing bugs, adding functionality or improving system quality. Systems often need to be shown to comply with regulatory standards. Along with demonstrating compliance, an artifact, called an assurance case, is often produced to show that the system indeed satisfies the property imposed by the standard (e.g., safety, privacy, security, etc.). Since each of the system, the standard, and the assurance case can be presented as a model, we propose the extension and use of traditional model management operators to aid in the reuse of parts of the assurance case when the system undergoes an evolution. Specifically, we present a model management approach that eventually produces a partial evolved assurance case and guidelines to help the assurance engineer in completing it. We demonstrate how our approach works on an automotive subsystem regulated by the ISO 26262 standard.

Fredericks, Erik M..  2016.  Automatically Hardening a Self-adaptive System Against Uncertainty. Proceedings of the 11th International Symposium on Software Engineering for Adaptive and Self-Managing Systems. :16–27.

A self-adaptive system (SAS) can reconfigure to adapt to potentially adverse conditions that can manifest in the environment at run time. However, the SAS may not have been explicitly developed with such conditions in mind, thereby requiring additional configuration states or updates to the requirements specification for the SAS to provide assurance that it continually satisfies its requirements and delivers acceptable behavior. By discovering both adverse environmental conditions and the SAS configuration states that can mitigate those conditions at design time, an SAS can be hardened against uncertainty prior to deployment, effectively extending its lifetime. This paper introduces two search-based techniques, Ragnarok and Valkyrie, for hardening an SAS against uncertainty. Ragnarok automatically discovers adverse conditions that negatively impact an SAS by searching for environmental conditions that explicitly cause requirements violations. Valkyrie then searches for SAS configurations that improve requirements satisficement throughout execution in response to discovered adverse environmental conditions. Together, these techniques can be used to improve the design and implementation of an SAS. We apply each technique to an industry-provided remote data mirroring application that can self-reconfigure in response to unknown or adverse conditions, such as network message delays, network link failures, and sensor noise.

Shevtsov, Stepan.  2016.  Developing a Reusable Control-based Approach to Build Self-adaptive Software Systems with Formal Guarantees. Proceedings of the 2016 24th ACM SIGSOFT International Symposium on Foundations of Software Engineering. :1060–1062.

An increasingly important concern of software engineers is handling uncertainty at runtime. Over the last decade researchers have applied architecture-based self-adaptation approaches to address this concern. However, providing guarantees required by current software systems has shown to be challenging with these approaches. To tackle this challenge, we study the application of control theory to realize self-adaptation and develop novel control-based adaptation mechanisms that guarantee desired system properties. Results are validated on systems with strict requirements.

Padekar, Hitesh, Park, Younghee, Hu, Hongxin, Chang, Sang-Yoon.  2016.  Enabling Dynamic Access Control for Controller Applications in Software-Defined Networks. Proceedings of the 21st ACM on Symposium on Access Control Models and Technologies. :51–61.

Recent findings have shown that network and system attacks in Software-Defined Networks (SDNs) have been caused by malicious network applications that misuse APIs in an SDN controller. Such attacks can both crash the controller and change the internal data structure in the controller, causing serious damage to the infrastructure of SDN-based networks. To address this critical security issue, we introduce a security framework called AEGIS to prevent controller APIs from being misused by malicious network applications. Through the run-time verification of API calls, AEGIS performs a fine-grained access control for important controller APIs that can be misused by malicious applications. The usage of API calls is verified in real time by sophisticated security access rules that are defined based on the relationships between applications and data in the SDN controller. We also present a prototypical implementation of AEGIS and demonstrate its effectiveness and efficiency by performing six different controller attacks including new attacks we have recently discovered.

Sonchack, John, Aviv, Adam J., Keller, Eric.  2016.  Timing SDN Control Planes to Infer Network Configurations. Proceedings of the 2016 ACM International Workshop on Security in Software Defined Networks & Network Function Virtualization. :19–22.

In this paper, we study information leakage by control planes of Software Defined Networks. We find that the response time of an OpenFlow control plane depends on its workload, and we develop an inference attack that an adversary with control of a single host could use to learn about network configurations without needing to compromise any network infrastructure (i.e. switches or controller servers). We also demonstrate that our inference attack works on real OpenFlow hardware. To our knowledge, no previous work has evaluated OpenFlow inference attacks outside of simulation.

Li, Wenjie, Qin, Zheng, Yin, Hui, Li, Rui, Ou, Lu, Li, Heng.  2016.  An Approach to Rule Placement in Software-Defined Networks. Proceedings of the 19th ACM International Conference on Modeling, Analysis and Simulation of Wireless and Mobile Systems. :115–118.

Software-Defined Networks (SDN) is a trend of research in networks. Rule placement, a common operation for network administrators, has become more complicated due to the capacity limitation of devices in which the large number of rules are deployed. Prior works on rule placement mostly consider the influence on rule placement incurred by the rules in a single device. However, the position relationships between neighbor devices have influences on rule placement. Our basic idea is to classify the position relationships into two categories: the serial relationship and the parallel relationship, and we present a novel strategy for rule placement based on the two different position relationships. There are two challenges of implementing our strategies: to check whether a rule is contained by a rule set or not and to check whether a rule can be merged by other rules or not.To overcome the challenges, we propose a novel data structure called OPTree to represent the rules, which is convenient to check whether a rule is covered by other rules. We design the insertion algorithm and search algorithm for OPTree. Extensive experiments show that our approach can effectively reduce the number of rules while ensuring placed rules work. On the other hand, the experimental results also demonstrate that it is necessary to consider the position relationships between neighbor devices when placing rules.

Cox, Jr., Jacob H., Clark, Russell J., Owen, III, Henry L..  2016.  Leveraging SDN to Improve the Security of DHCP. Proceedings of the 2016 ACM International Workshop on Security in Software Defined Networks & Network Function Virtualization. :35–38.

Current State of the art technologies for detecting and neutralizing rogue DHCP servers are tediously complex and prone to error. Network operators can spend hours (even days) before realizing that a rogue server is affecting their network. Additionally, once network operators suspect that a rogue server is active on their network, even more hours can be spent finding the server's MAC address and preventing it from affecting other clients. Not only are such methods slow to eliminate rogue servers, they are also likely to affect other clients as network operators shutdown services while attempting to locate the server. In this paper, we present Network Flow Guard (NFG), a simple security application that utilizes the software defined networking (SDN) paradigm of programmable networks to detect and disable rogue servers before they are able to affect network clients. Consequently, the key contributions of NFG are its modular approach and its automated detection/prevention of rogue DHCP servers, which is accomplished with little impact to network architecture, protocols, and network operators.

Pan, Xiang, Yegneswaran, Vinod, Chen, Yan, Porras, Phillip, Shin, Seungwon.  2016.  HogMap: Using SDNs to Incentivize Collaborative Security Monitoring. Proceedings of the 2016 ACM International Workshop on Security in Software Defined Networks & Network Function Virtualization. :7–12.

Cyber Threat Intelligence (CTI) sharing facilitates a comprehensive understanding of adversary activity and enables enterprise networks to prioritize their cyber defense technologies. To that end, we introduce HogMap, a novel software-defined infrastructure that simplifies and incentivizes collaborative measurement and monitoring of cyber-threat activity. HogMap proposes to transform the cyber-threat monitoring landscape by integrating several novel SDN-enabled capabilities: (i) intelligent in-place filtering of malicious traffic, (ii) dynamic migration of interesting and extraordinary traffic and (iii) a software-defined marketplace where various parties can opportunistically subscribe to and publish cyber-threat intelligence services in a flexible manner. We present the architectural vision and summarize our preliminary experience in developing and operating an SDN-based HoneyGrid, which spans three enterprises and implements several of the enabling capabilities (e.g., traffic filtering, traffic forwarding and connection migration). We find that SDN technologies greatly simplify the design and deployment of such globally distributed and elastic HoneyGrids.

Han, Wonkyu, Zhao, Ziming, Doupé, Adam, Ahn, Gail-Joon.  2016.  HoneyMix: Toward SDN-based Intelligent Honeynet. Proceedings of the 2016 ACM International Workshop on Security in Software Defined Networks & Network Function Virtualization. :1–6.

Honeynet is a collection of honeypots that are set up to attract as many attackers as possible to learn about their patterns, tactics, and behaviors. However, existing honeypots suffer from a variety of fingerprinting techniques, and the current honeynet architecture does not fully utilize features of residing honeypots due to its coarse-grained data control mechanisms. To address these challenges, we propose an SDN-based intelligent honeynet called HoneyMix. HoneyMix leverages the rich programmability of SDN to circumvent attackers' detection mechanisms and enables fine-grained data control for honeynet. To do this, HoneyMix simultaneously establishes multiple connections with a set of honeypots and selects the most desirable connection to inspire attackers to remain connected. In this paper, we present the HoneyMix architecture and a description of its core components.

Karmakar, Kallol Krishna, Varadharajan, Vijay, Tupakula, Udaya, Hitchens, Michael.  2016.  Policy Based Security Architecture for Software Defined Networks. Proceedings of the 31st Annual ACM Symposium on Applied Computing. :658–663.

Software Defined Network(SDN) is a promising technological advancement in the networking world. It is still evolving and security is a major concern for SDN. In this paper we proposed policy based security architecture for securing the SDN domains. Our architecture enables the administrator to enforce different types of policies such as based on the devices, users, location and path for securing the communication in SDN domain. Our architecture is developed as an application that can be run on any of the SDN Controllers. We have implemented our architecture using the POX Controller and Raspberry Pi 2 switches. We will present different case scenarios to demonstrate fine granular security policy enforcement with our architecture.

Hafeez, Ibbad, Ding, Aaron Yi, Suomalainen, Lauri, Kirichenko, Alexey, Tarkoma, Sasu.  2016.  Securebox: Toward Safer and Smarter IoT Networks. Proceedings of the 2016 ACM Workshop on Cloud-Assisted Networking. :55–60.

In this paper we present Securebox, an affordable and deployable platform for securing and managing IoT networks. Our proposal targets an alarming spot in the fast growing IoT industry where security is often overlooked due to device limitation, budget constraint, and development deadline. In contrast to existing host-centric and hardware-coupled solutions, Securebox empowers a cloud-assisted "charge for network service" model that is dedicated to budget and resource constrained IoT environments. Owing to its cloud-driven and modular design, Securebox allows us to 1) flexibly offload and onload security and management functions to the cloud and network edge components; 2) offer advanced security and management services to end users in an affordable and on-demand manner; 3) ease the upgrade and deployment of new services to guard against abrupt security breakouts. To demonstrate Securebox, we have implemented the platform consisting of a plug-n-play frontend, a Kubernetes-powered backend cluster, and a smartphone mobile application. Based on the testbed evaluation, we show that Securebox is robust and responsive. Its collaborative and extensible architecture enforces rapid update cycles and can scale with the growing diversity of IoT devices.

Liu, Bingyang, Bi, Jun, Zhou, Yu.  2016.  Source Address Validation in Software Defined Networks. Proceedings of the 2016 ACM SIGCOMM Conference. :595–596.

In this paper, we present the preliminary design and implementation of SDN-SAVI, an SDN application that enables SAVI functionalities in SDN networks. In this proposal, all the functionalities are implemented on the controller without modifying SDN switches. To enforce SAVI on packets in the data plane, the controller installs binding tables in switches using existing SDN techniques, such as OpenFlow. With SDN-SAVI, a network administrator can now enforce SAVI in her network by merely integrating a module on the controller, rather than purchasing SAVI-capable switches and replacing legacy ones.

Shukla, Apoorv, Schmid, Stefan, Feldmann, Anja, Ludwig, Arne, Dudycz, Szymon, Schuetze, Andre.  2016.  Towards Transiently Secure Updates in Asynchronous SDNs. Proceedings of the 2016 ACM SIGCOMM Conference. :597–598.

Software-Defined Networks (SDNs) promise to overcome the often complex and error-prone operation of tradi- tional computer networks, by enabling programmabil- ity, automation and verifiability. Yet, SDNs also in- troduce new challenges, for example due to the asyn- chronous communication channel between the logically centralized control platform and the switches in the data plane. In particular, the asynchronous commu- nication of network update commands (e.g., OpenFlow FlowMod messages) may lead to transient inconsisten- cies, such as loops or bypassed waypoints (e.g., fire- walls). One approach to ensure transient consistency even in asynchronous environments is to employ smart scheduling algorithms: algorithms which update subsets of switches in each communication round only, where each subset in itself guarantees consistency. In this demo, we show how to change routing policies in a transiently consistent manner. We demonstrate two al- gorithms, namely, Wayup [5] and Peacock [4], which partition the network updates sent from SDN controller towards OpenFlow software switches into multiple rounds as per respective algorithms. Later, the barrier mes- sages are utilized to ensure reliable network updates.

Shimada, Isamu, Higaki, Hiroaki.  2016.  Intentional Collisions for Secure Ad-Hoc Networks. Adjunct Proceedings of the 13th International Conference on Mobile and Ubiquitous Systems: Computing Networking and Services. :183–188.

In ad-hoc networks, data messages are transmitted from a source wireless node to a destination one along a wireless multihop transmission route consisting of a sequence of intermediate wireless nodes. Each intermediate wireless node forwards data messages to its next-hop wireless node. Here, a wireless signal carrying the data message is broadcasted by using an omni antenna and it is not difficult for a eavesdropper wireless node to overhear the wireless signal to get the data message. Some researches show that it is useful to transmit noise wireless signal which collide to the data message wireless signal in order for interfering the overhearing. However, some special devices such as directional antennas and/or high computation power for complicated signal processing are required. For wireless multihop networks with huge number of wireless nodes, small and cheap wireless nodes are mandatory for construction of the network. This paper proposes the method for interfering the overhearing by the eavesdropper wireless nodes where routing protocol and data message transmission protocol with cooperative noise signal transmissions by 1-hop and 2-hop neighbor wireless nodes of each intermediate wireless node.

Zhang, Dajun, Yu, Fei Richard, Wei, Zhexiong, Boukerche, Azzedine.  2016.  Software-defined Vehicular Ad Hoc Networks with Trust Management. Proceedings of the 6th ACM Symposium on Development and Analysis of Intelligent Vehicular Networks and Applications. :41–49.

With the rising interest of expedient, safe, and high-efficient transportation, vehicular ad hoc networks (VANETs) have turned into a critical technology in smart transportation systems. Because of the high mobility of nodes, VANETs are vulnerable to security attacks. In this paper, we propose a novel framework of software-defined VANETs with trust management. Specifically, we separate the forwarding plane in VANETs from the control plane, which is responsible for the control functionality, such as routing protocols and trust management in VANETs. Using the on-demand distance vector routing (TAODV) protocol as an example, we present a routing protocol named software-defined trust based ad hoc on-demand distance vector routing (SD-TAODV). Simulation results are presented to show the effectiveness of the proposed software-defined VANETs with trust management.

Sterbenz, James P.G..  2016.  Drones in the Smart City and IoT: Protocols, Resilience, Benefits, and Risks. Proceedings of the 2Nd Workshop on Micro Aerial Vehicle Networks, Systems, and Applications for Civilian Use. :3–3.

Drones have quickly become ubiquitous for both recreational and serious use. As is frequently the case with new technology in general, their rapid adoption already far exceeds our legal, policy, and social ability to cope with such issues as privacy and interference with well-established commercial and military air space. While the FAA has issued rulings, they will almost certainly be challenged in court as disputes arise, for example, when property owners shoot drones down. It is clear that drones will provide a critical role in smart cities and be connected to, if not directly a part of the IoT (Internet of Things). Drones will provide an essential role in providing network relay connectivity and situational awareness, particularly in disaster assessment and recovery scenarios. As is typical for new network technologies, the deployment of the drone hardware far exceeds our research in protocols – extending our previous understanding of MANETs (mobile ad hoc networks) and DTNs (disruption tolerant networks) – and more importantly, management, control, resilience, security, and privacy concerns. This keynote address will discuss these challenges and consider future research directions.

Zhao, Dexin, Ma, Zhen, Zhang, Degan.  2016.  A Distributed and Adaptive Trust Evaluation Algorithm for MANET. Proceedings of the 12th ACM Symposium on QoS and Security for Wireless and Mobile Networks. :47–54.

We propose a distributed and adaptive trust evaluation algorithm (DATEA) to calculate the trust between nodes. First, calculate the communication trust by using the number of data packets between nodes, and predict the trust based on the trend of this value, calculate the comprehensive trust by combining the history trust with the predict value; calculate the energy trust based on the residual energy of nodes; calculate the direct trust by using the communication trust and energy trust. Second, calculate the recommendation trust based on the recommendation reliability and the recommendation familiarity; put forward the adaptively weighting method, and calculate the integrate direct trust by combining the direct trust with recommendation trust. Third, according to the integrate direct trust, considering the factor of trust propagation distance, the indirect trust between nodes is calculated. Simulation experiments show that the proposed algorithm can effectively avoid the attacks of malicious nodes, besides, the calculated direct trust and indirect trust about normal nodes are more conformable to the actual situation.

Xu, Guangwu, Yan, Zheng.  2016.  A Survey on Trust Evaluation in Mobile Ad Hoc Networks. Proceedings of the 9th EAI International Conference on Mobile Multimedia Communications. :140–148.

Mobile Ad Hoc Network (MANET) is a multi-hop temporary and autonomic network comprised of a set of mobile nodes. MANETs have the features of non-center, dynamically changing topology, multi-hop routing, mobile nodes, limited resources and so on, which make it face more threats. Trust evaluation is used to support nodes to cooperate in a secure and trustworthy way through evaluating the trust of participating nodes in MANETs. However, many trust evaluation models proposed for MANETs still have many problems and shortcomings. In this paper, we review the existing researches, then analyze and compare the proposed trust evaluation models by presenting and applying uniform criteria in order to point out a number of open issues and challenges and suggest future research trends.

Cao, Xuanyu, Zhang, Jinbei, Fu, Luoyi, Wu, Weijie, Wang, Xinbing.  2016.  Optimal Secrecy Capacity-delay Tradeoff in Large-scale Mobile Ad Hoc Networks. IEEE/ACM Trans. Netw.. 24:1139–1152.

In this paper, we investigate the impact of information-theoretic secrecy constraint on the capacity and delay of mobile ad hoc networks (MANETs) with mobile legitimate nodes and static eavesdroppers whose location and channel state information (CSI) are both unknown. We assume n legitimate nodes move according to the fast i.i.d. mobility pattern and each desires to communicate with one randomly selected destination node. There are also nv static eavesdroppers located uniformly in the network and we assume the number of eavesdroppers is much larger than that of legitimate nodes, i.e., v textgreater 1. We propose a novel simple secure communication model, i.e., the secure protocol model, and prove its equivalence to the widely accepted secure physical model under a few technical assumptions. Based on the proposed model, a framework of analyzing the secrecy capacity and delay in MANETs is established. Given a delay constraint D, we find that the optimal secrecy throughput capacity is [EQUATION](W((D/n))(2/3), where W is the data rate of each link. We observe that: 1) the capacity-delay tradeoff is independent of the number of eavesdroppers, which indicates that adding more eavesdroppers will not degenerate the performance of the legitimate network as long as v textgreater 1; 2) the capacity-delay tradeoff of our paper outperforms the previous result Θ((1/nψe)) in [11], where ψe = nv–1 = ω(1) is the density of the eavesdroppers. Throughout this paper, for functions f(n) and G(n), we denote f(n) = o(g(n)) if limn→∞ (f(n)/g(n)) = 0; f(n) = ω(g(n)) if g(n) = o(f(n)); f(n) = O(g(n)) if there is a positive constant c such that f(n) ≤ cg(n) for sufficiently large n; f(n) = Ω(g(n))if g(n) = O(f(n)); f(n) = Θ(g(n) if both f(n) = O(g(n)) and f(n) = Omega;(g(n)) hold. Besides, the order notation [EQUATION] omits the polylogarithmic factors for better readability.