Achieving high performance in cryptographic processing is important due to the increasing connectivity among today’s computers. Despite steady improvements in microprocessor and system performance, private-key cipher implementations continue to be slow. Irrespective of the cipher used, the main reason for the low performance is lack of parallelism, which fundamentally comes from encryption modes such as the Cipher Block Chaining (CBC) mode. In CBC, each plaintext block is XOR’ed with the previous ciphertext block and then encrypted, essentially inducing a tight recurrence through the ciphertext blocks. To deliver high performance while maintaining high level of security assurance in real systems, the cryptography community has proposed Interleaved Cipher Block Chaining (ICBC) mode. In four-way interleaved chaining, the first, fifth, and every fourth block thereafter are encrypted in CBC mode; the second, sixth, and every fourth block thereafter are encrypted as another stream, and so on. Thus, interleaved chaining loosens the recurrence imposed by CBC, enabling the multiple encryption streams to be overlapped. The number of interleaved chains can be chosen to balance performance and adequate chaining to get good data diffusion. While ICBC was originally proposed to improve hardware encryption rates by employing multiple encryption chips in parallel, this is the first paper to evaluate ICBC via multithreading commonly-used ciphers on a symmetric multiprocessor (SMP). ICBC allows exploiting the full processing power of SMPs, which spend many cycles in cryptographic processing as medium-scale servers today, and will do so as chip-multiprocessor clients in the future. Using the Wisconsin Wind Tunnel II, we show that our multithreaded ciphers achieve encryption rates of 92 Mbytes/s on a 16-processor SMP at 1 GHz, reaching a factor of almost 10 improvement oiler a uniprocessor, which achieves 9 Mbytes/s.

We show that malicious participants in a peer-to-peer system can subvert its membership management mechanisms to create large-scale DDoS attacks on nodes not even part of the overlay system. The attacks exploit many fundamental design choices made by peer-to-peer system designers such as (i) use of push-based mechanisms; (ii) use of distinct logical identifier (e.g. IDs in a DHT) corresponding to the same physical identifier (e.g., IP address), typically to handle hosts behind NATs; and (iii) inadequate or poorly designed mechanisms to validate membership information. We demonstrate the significance of the attacks in the context of mature and extensively deployed peer-to-peer systems with representative and contrasting membership management algorithms - DHT-based Kad and gossip-based ESM.

Machines that provide TCP services are often susceptible to various types of Denial of Service attacks from external hosts on the network. One particular type of attack is known as a SYN flood, where external hosts attempt to overwhelm the server machine by sending a constant stream of TCP connection requests, forcing the server to allocate resources for each new connection until all resources are exhausted. This paper discusses several approaches for dealing with the exhaustion problem, including SYN caches and SYN cookies. The advantages and drawbacks of each approach are presented, and the implementation of the specific solution used in FreeBSD is analyzed.

In multihop wireless systems, such as ad hoc and sensor networks, the need for cooperation among nodes to relay each other’s packets exposes them to a wide range of security attacks. A particularly devastating attack is known as the wormhole attack, where a malicious node records control and data traffic at one location and tunnels it to a colluding node far away, which replays it locally. This can either disrupt route establishment or make routes pass through the malicious nodes. In this paper, we present a lightweight countermeasure for the wormhole attack, called LiteWorp, which relies on overhearing neighbor communication. LiteWorp is particularly suitable for resource-constrained multihop wireless networks, such as sensor networks. Our solution allows detection of the wormhole, followed by isolation of the malicious nodes. Simulation results show that every wormhole is detected and isolated within a very short period of time over a large range of scenarios. The results also show that the fraction of packets lost due to the wormhole when LiteWorp is applied is negligible compared to the loss in an unprotected network. Simulation results bring out the configuration where no framing is possible, while still having high detection rate. Analysis is done to show the low resource consumption of LiteWorp, the low detection latency, and the likelihood of framing by malicious nodes.

There is an inherent trade-off between epidemic and deterministic tree-based broadcast primitives. Tree-based approaches have a small message complexity in steady-state but are very fragile in the presence of faults. Gossip, or epidemic, protocols have a higher message complexity but also offer much higher resilience.

This paper proposes an integrated broadcast scheme that combines both approaches. We use a low cost scheme to build and maintain broadcast trees embedded on a gossipbased overlay. The protocol sends the message payload preferably via tree branches but uses the remaining links of the gossip overlay for fast recovery and expedite tree healing. Experimental evaluation presented in the paper shows that our new strategy has a low overhead and that is able to support large number of faults while maintaining a high reliability.

Sensor networks enable a wide range of applications in both military and civilian domains. However, the deployment scenarios, the functionality requirements, and the limited capabilities of these networks expose them to a wide-range of attacks against control traffic (such as wormholes, Sybil attacks, rushing attacks, etc). In this paper we propose a lightweight protocol called DICAS that mitigates these attacks by detecting, diagnosing, and isolating the malicious nodes. DICAS uses as a fundamental building block the ability of a node to oversee its neighboring nodes’ communication. On top of DICAS, we build a secure routing protocol, LSR, which in addition supports multiple node-disjoint paths. We analyze the security guarantees of DICAS and use ns-2 simulations to show its effectiveness against three representative attacks. Overhead analysis is conducted to prove the lightweight nature of DICAS.

This paper proposes a model for teaching information assurance ethics. The model is composed of four dimensions: the moral development dimension; the ethical dimension; the security dimension; and the solutions dimension. The ethical dimension explores the ethical ramifications of a topic from a variety of perspectives. The security dimension includes ways in which an information assurance topic manifests to information assurance professionals. The solutions dimension focuses on remedies that individuals, groups of individuals and society have created to address security problems and associated ethical dilemmas. The moral development dimension describes the stages and transitions that humans experience as they develop morally, as they develop their own personal beliefs and behaviors about right and wrong.

This paper presents an innovative access control model, referred to as Web service Access Control Version 1 (Ws-AC1), specifically tailored to Web services. The most distinguishing features of this model are the flexible granularity in protection objects and negotiation capabilities. Under Ws-AC1, an authorization can be associated with a single service and can specify for which parameter values the service can be authorized for use, thus providing a fine access control granularity. Ws-AC1 also supports coarse granularities in protection objects in that it provides the notion of service class under which several services can be grouped. Authorizations can then be associated with a service class and automatically propagated to each element in the class. The negotiation capabilities of Ws-AC1 are related to the negotiation of identity attributes and the service parameters. Identity attributes refer to information that a party requesting a service may need to submit in order to obtain the service. The access control policy model of Ws-AC1 supports the specification of policies in which conditions are stated, specifying the identity attributes to be provided and constraints on their values. In addition, conditions may also be specified against context parameters, such as time. To enhance privacy and security, the actual submission of these identity attributes is executed through a negotiation process. Parameters may also be negotiated when a subject requires use of a service with certain parameters values that, however, are not authorized under the policies in place. In this paper, we provide the formal definitions underlying our model and the relevant algorithms, such as the access control algorithm. We also present an encoding of our model in the Web Services Description Language (WSDL) standard for which we develop an extension, required to support Ws-AC1.

The authors look more closely at determining an appropriate scope and sequence for information assurance (IA) and briefly describe a project whose goal is the articulation of an IA curriculum.

This paper will overview general evaluation purposes, elements, and steps for designing an evaluation in order to provide foundational information that can be used to conduct an evaluation of any security awareness, training, or education programs.

Given the high cost of producing software, development of technology for prevention of software piracy is important for the software industry. In this paper we present a novel approach for preventing the creation of unauthorized copies of software. Our approach splits software modules into open and hidden components. The open components are installed (executed) on an insecure machine while the hidden components are installed (executed) on a secure machine. We assume that while open components can be stolen, to obtain a fully functioning copy of the software, the hidden components must be recovered. We describe an algorithm that constructs hidden components by slicing the original software components. We argue that recovery of hidden components constructed through slicing, in order to obtain a fully functioning copy of the software, is a complex task. We further develop security analysis to capture the complexity of recovering hidden components. Finally we apply our technique to several large Java programs to study the complexity of recovering constructed hidden components and to measure the runtime overhead introduced by splitting of software into open and hidden components.