Abstract:Network-based intrusion has become a serious threat to today's highly networked information systems, yet the overwhelming majority of current network security mechanisms are "passive" in response to network-based attacks. In particular, tracing and detection of the source of network-based intrusion has been left largely untouched in existing intrusion detection mechanisms. The fact that intruders can log in through a series of hosts before attacking the final target makes it extremely difficult to trace back the real source of network-based intrusions.In this paper, we apply active networking principles to address the problem of tracing network-based intrusion with such chained connections, and propose a novel intrusion response framework: Sleepy Watermark Tracing (SWT). SWT is "sleepy" in that it does not introduce overhead when no intrusion is detected. Yet it is "active" in that when an intrusion is detected, the target will inject a watermark into the backward connection of the intrusion, and wake up and collaborate with intermediate routers along the intrusion path. By integrating a sleepy intrusion response scheme, a watermark correlation technique and an active tracing protocol, SWT provides a highly efficient and accurate source tracing on interactive intrusions through chained telnet or rlogin. Our *

We describe the successful mixing of polymer pairs and triplets that are normally incompatible to form blends that possess molecular‐level homogeneity. This is achieved by the simultaneous formation of crystalline inclusion compounds (ICs) between host cyclodextrins (CDs) and two or more guest polymers, followed by coalescing the included guest polymers from their common CD–ICs to form blends. Several such CD–IC fabricated blends, including both polymer1/polymer2 binary and polymer1/ polymer2/polymer3 ternary blends, are described and examined by means of X‐ray diffraction, differential scanning calorimetry, thermogravimetric analysis, Fourier transform infrared spectroscopy, and solid‐state NMR to probe their levels of mixing. It is generally observed that homogeneous blends with a molecular‐level mixing of blend components is achieved, even when the blend components are normally immiscible by the usual solution and melt blending techniques. In addition, when block copolymers composed of inherently immiscible blocks are coalesced from their CD–ICs, significant suppression of their normal phase‐segregated morphologies generally occurs. Preliminary observations of the thermal and temporal stabilities of the CD–IC coalesced blends and block copolymers are reported, and CD–IC fabrication of polymer blends and reorganization of block copolymers are suggested as a potentially novel means to achieve a significant expansion of the range of useful polymer materials. © 2004 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 42: 4207–4224, 2004

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DECIDUOUS is a security management framework for identifying the sources of network-based intrusions. The first key concept in DECIDU-OUS is dynamic security associations, which efficiently and collectively provide location information for attack sources. DECIDUOUS is built on top of IETF's IPSEC/ISAKMP infrastructure, and it does not introduce any new network protocol for source identification in a single administrative domain. It defines a collaborative protocol for inter-domain attack source identification. The second key concept in DECIDUOUS is the management information integration of the intrusion detection system (IDS) and attack source identification system (ASIS) across different protocol layers. For example, in DECIDUOUS, it is possible for a network-layer security control protocol (e.g., IPSEC) to collaborate with an application-layer intrusion detection system module (e.g., IDS for the SNMP engine). In this paper, we present the motivations, design, and prototype implementation of the DECIDUOUS framework.K e y Words: