Jennifer Chong, P. Pal, M. Atighetchi, P. Rubel, F. Webber
Many techniques and mechanisms exist today, some COTS, others less mature research products that can be used to deflect, detect, or even recover from specific types of cyber attacks. None of them individually is sufficient to provide an all around defense for a mission critical distributed system. A mission critical system must operate despite sustained attacks throughout the mission cycle, which in the case of military systems, can range from hours to days. A comprehensive survivability architecture, where individual security tools and defense mechanisms are used as building blocks, is required to achieve this level of survivability. We have recently designed a survivability architecture, which combined elements of protection, detection, and adaptive reaction; and applied it to a DoD information system. The resulting defense-enabled system was first evaluated internally, and then deployed for external Red Team exercise. In this paper we describe the survivability architecture of the system, and explain the rationale that motivated the design
{"title":"Survivability architecture of a mission critical system: the DPASA example","authors":"Jennifer Chong, P. Pal, M. Atighetchi, P. Rubel, F. Webber","doi":"10.1109/CSAC.2005.54","DOIUrl":"https://doi.org/10.1109/CSAC.2005.54","url":null,"abstract":"Many techniques and mechanisms exist today, some COTS, others less mature research products that can be used to deflect, detect, or even recover from specific types of cyber attacks. None of them individually is sufficient to provide an all around defense for a mission critical distributed system. A mission critical system must operate despite sustained attacks throughout the mission cycle, which in the case of military systems, can range from hours to days. A comprehensive survivability architecture, where individual security tools and defense mechanisms are used as building blocks, is required to achieve this level of survivability. We have recently designed a survivability architecture, which combined elements of protection, detection, and adaptive reaction; and applied it to a DoD information system. The resulting defense-enabled system was first evaluated internally, and then deployed for external Red Team exercise. In this paper we describe the survivability architecture of the system, and explain the rationale that motivated the design","PeriodicalId":422994,"journal":{"name":"21st Annual Computer Security Applications Conference (ACSAC'05)","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2005-12-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131266363","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
S. Foley, Abe Singer, M. Locasto, Stelios Sidiroglou, A. Keromytis, J. McDermott, Julie Thorpe, P. V. Oorschot, Anil Somayaji, R. Ford, M. Bush, Alex Boulatov
This panel highlights a selection of the most interesting and provocative papers from the 2005 New Security Paradigms Workshop. This workshop was held September 2005 - the URL for more information is http://www.nspw.org. The panel consists of authors of the selected papers, and the session is moderated by the workshop's general chairs. We present selected papers focusing on exciting major themes that emerged from the workshop. These are the papers that will provoke the most interesting discussion at ACSAC.
{"title":"Highlights from the 2005 New Security Paradigms Workshop","authors":"S. Foley, Abe Singer, M. Locasto, Stelios Sidiroglou, A. Keromytis, J. McDermott, Julie Thorpe, P. V. Oorschot, Anil Somayaji, R. Ford, M. Bush, Alex Boulatov","doi":"10.1109/CSAC.2005.29","DOIUrl":"https://doi.org/10.1109/CSAC.2005.29","url":null,"abstract":"This panel highlights a selection of the most interesting and provocative papers from the 2005 New Security Paradigms Workshop. This workshop was held September 2005 - the URL for more information is http://www.nspw.org. The panel consists of authors of the selected papers, and the session is moderated by the workshop's general chairs. We present selected papers focusing on exciting major themes that emerged from the workshop. These are the papers that will provoke the most interesting discussion at ACSAC.","PeriodicalId":422994,"journal":{"name":"21st Annual Computer Security Applications Conference (ACSAC'05)","volume":"96 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2005-12-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131287414","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Understanding the security goals provided by cryptographic protocol implementations is known to be difficult, since security requirements such as secrecy, integrity and authenticity of data are notoriously hard to establish, especially in the context of cryptographic interactions. A lot of research has been devoted to developing formal techniques to analyze abstract specifications of cryptographic protocols. Less attention has been paid to the analysis of cryptoprotocol implementations, for which a formal link to specifications is often not available. In this paper, we apply an approach to determine security goals provided by a C implementation to an industrially-strength biometric authentication system. Our approach is based on control flow graphs and automated theorem provers for first-order logic
{"title":"Code security analysis of a biometric authentication system using automated theorem provers","authors":"J. Jürjens","doi":"10.1109/CSAC.2005.15","DOIUrl":"https://doi.org/10.1109/CSAC.2005.15","url":null,"abstract":"Understanding the security goals provided by cryptographic protocol implementations is known to be difficult, since security requirements such as secrecy, integrity and authenticity of data are notoriously hard to establish, especially in the context of cryptographic interactions. A lot of research has been devoted to developing formal techniques to analyze abstract specifications of cryptographic protocols. Less attention has been paid to the analysis of cryptoprotocol implementations, for which a formal link to specifications is often not available. In this paper, we apply an approach to determine security goals provided by a C implementation to an industrially-strength biometric authentication system. Our approach is based on control flow graphs and automated theorem provers for first-order logic","PeriodicalId":422994,"journal":{"name":"21st Annual Computer Security Applications Conference (ACSAC'05)","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2005-12-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129375558","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
An increasing variety of malware, such as worms, spyware and adware, threatens both personal and business computing. Remotely controlled bot networks of compromised systems are growing quickly. In this paper, we tackle the problem of automated detection of break-ins caused by unknown malware targeting personal computers. We develop a host based system, BINDER (Break-IN DEtectoR), to detect break-ins by capturing user unintended malicious outbound connections (referred to as extrusions). To infer user intent, BINDER correlates outbound connections with user-driven input at the process level under the assumption that user intent is implied by user-driven input. Thus BINDER can detect a large class of unknown malware such as worms, spyware and adware without requiring signatures. We have successfully used BINDER to detect real world spyware on daily used computers and email worms on a controlled testbed with very small false positives
{"title":"Design and implementation of an extrusion-based break-in detector for personal computers","authors":"Weidong Cui, R. Katz, Wai-tian Tan","doi":"10.1109/CSAC.2005.19","DOIUrl":"https://doi.org/10.1109/CSAC.2005.19","url":null,"abstract":"An increasing variety of malware, such as worms, spyware and adware, threatens both personal and business computing. Remotely controlled bot networks of compromised systems are growing quickly. In this paper, we tackle the problem of automated detection of break-ins caused by unknown malware targeting personal computers. We develop a host based system, BINDER (Break-IN DEtectoR), to detect break-ins by capturing user unintended malicious outbound connections (referred to as extrusions). To infer user intent, BINDER correlates outbound connections with user-driven input at the process level under the assumption that user intent is implied by user-driven input. Thus BINDER can detect a large class of unknown malware such as worms, spyware and adware without requiring signatures. We have successfully used BINDER to detect real world spyware on daily used computers and email worms on a controlled testbed with very small false positives","PeriodicalId":422994,"journal":{"name":"21st Annual Computer Security Applications Conference (ACSAC'05)","volume":"13 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2005-12-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"117323005","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Online email archives are an under-protected yet extremely sensitive information resource. Email archives can store years worth of personal and business email in an easy-to-access form, one that is much easier to compromise than messages being transmitted "on the wire." Most email archives, however, are protected by reusable passwords that are often weak and can be easily compromised. To protect such archives, we propose a novel user-specific design for an anomaly-based email archive intrusion detection system. As a first step towards building such a system, we have developed a simple probabilistic model of user email behavior that correlates email senders and a user's disposition of emails. In tests using data gathered from three months of observed user behavior and synthetic models of attacker behavior, this model exhibits a low rate of false positives (generally one false alarm every few weeks) while still detecting most attacks. These results suggest that anomaly detection is a feasible strategy for securing email archives, one that does not require changes in user authentication or access behavior
{"title":"Securing email archives through user modeling","authors":"Yiru Li, Anil Somayaji","doi":"10.1109/CSAC.2005.50","DOIUrl":"https://doi.org/10.1109/CSAC.2005.50","url":null,"abstract":"Online email archives are an under-protected yet extremely sensitive information resource. Email archives can store years worth of personal and business email in an easy-to-access form, one that is much easier to compromise than messages being transmitted \"on the wire.\" Most email archives, however, are protected by reusable passwords that are often weak and can be easily compromised. To protect such archives, we propose a novel user-specific design for an anomaly-based email archive intrusion detection system. As a first step towards building such a system, we have developed a simple probabilistic model of user email behavior that correlates email senders and a user's disposition of emails. In tests using data gathered from three months of observed user behavior and synthetic models of attacker behavior, this model exhibits a low rate of false positives (generally one false alarm every few weeks) while still detecting most attacks. These results suggest that anomaly detection is a feasible strategy for securing email archives, one that does not require changes in user authentication or access behavior","PeriodicalId":422994,"journal":{"name":"21st Annual Computer Security Applications Conference (ACSAC'05)","volume":"328 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2005-12-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132584770","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Microscopic analysis of malicious code (malware) requires the aid of a variety of powerful tools. Chief among them is a debugger that enables runtime binary analysis at an instruction level. One of the important services provided by a debugger is the ability to stop execution of code at an arbitrary point during runtime, using breakpoints. Software breakpoints support an unlimited number of breakpoint locations by changing the code being debugged so that it can be interrupted during runtime. Most, if not all, malware are very sensitive to code modification with self-modifying and/or self-checking (SM-SC) capabilities, rendering the use of software breakpoints limited in their scope. Hardware breakpoints supported by the underlying processor, on the other hand, use a subset of the processor register set and exception mechanisms to provide breakpoints that do not entail code modification. This makes hardware breakpoints the most powerful breakpoint mechanism for malware analysis. However, current processors provide a very limited number of hardware breakpoints (typically 2-4 locations). Thus, a serious restriction is imposed on the debugger to set a desired number of breakpoints without resorting to the limited alternative of software breakpoints. Also, with the ever evolving nature of malware, there are techniques being employed that prevent the use of hardware breakpoints. This calls for a new breakpoint mechanism that retains the features of hardware breakpoints while providing an unlimited number of breakpoints, which cannot be detected or countered. In this paper, we present the concept of stealth breakpoints and discuss the design and implementation of VAMPiRE, a realization of this concept. VAMPiRE cannot be detected or countered and provides unlimited number of breakpoints to be set on code, data, and I/O with the same precision as that of hardware breakpoints. It does so by employing a subtle combination of simple stealth techniques using virtual memory and hardware single-stepping mechanisms that are available on all processors, old and new. This technique makes VAMPiRE portable to any architecture, providing powerful breakpoint ability similar to hardware breakpoints for microscopic malware analysis
{"title":"Stealth breakpoints","authors":"Amit Vasudevan, R. Yerraballi","doi":"10.1109/CSAC.2005.52","DOIUrl":"https://doi.org/10.1109/CSAC.2005.52","url":null,"abstract":"Microscopic analysis of malicious code (malware) requires the aid of a variety of powerful tools. Chief among them is a debugger that enables runtime binary analysis at an instruction level. One of the important services provided by a debugger is the ability to stop execution of code at an arbitrary point during runtime, using breakpoints. Software breakpoints support an unlimited number of breakpoint locations by changing the code being debugged so that it can be interrupted during runtime. Most, if not all, malware are very sensitive to code modification with self-modifying and/or self-checking (SM-SC) capabilities, rendering the use of software breakpoints limited in their scope. Hardware breakpoints supported by the underlying processor, on the other hand, use a subset of the processor register set and exception mechanisms to provide breakpoints that do not entail code modification. This makes hardware breakpoints the most powerful breakpoint mechanism for malware analysis. However, current processors provide a very limited number of hardware breakpoints (typically 2-4 locations). Thus, a serious restriction is imposed on the debugger to set a desired number of breakpoints without resorting to the limited alternative of software breakpoints. Also, with the ever evolving nature of malware, there are techniques being employed that prevent the use of hardware breakpoints. This calls for a new breakpoint mechanism that retains the features of hardware breakpoints while providing an unlimited number of breakpoints, which cannot be detected or countered. In this paper, we present the concept of stealth breakpoints and discuss the design and implementation of VAMPiRE, a realization of this concept. VAMPiRE cannot be detected or countered and provides unlimited number of breakpoints to be set on code, data, and I/O with the same precision as that of hardware breakpoints. It does so by employing a subtle combination of simple stealth techniques using virtual memory and hardware single-stepping mechanisms that are available on all processors, old and new. This technique makes VAMPiRE portable to any architecture, providing powerful breakpoint ability similar to hardware breakpoints for microscopic malware analysis","PeriodicalId":422994,"journal":{"name":"21st Annual Computer Security Applications Conference (ACSAC'05)","volume":"22 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2005-12-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133278731","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Signature-based schemes for detecting Internet worms often fail on zero-day worms, and their ability to rapidly react to new threats is typically limited by the requirement of some form of human involvement to formulate updated attack signatures. We propose an anomaly-based detection technique detailing a method to detect propagation of scanning worms within individual network cells, thus protecting internal networks from infection by internal clients. Our software implementation indicates that this technique is both accurate and rapid enough to enable automatic containment and suppression of worm propagation within a network cell. Our approach relies on an aggregate anomaly score, derived from the correlation of address resolution protocol (ARP) activity from individual network attached devices. Our preliminary analysis and prototype indicate that this technique can be used to rapidly detect zero-day worms within a very small number of scans
{"title":"Detecting intra-enterprise scanning worms based on address resolution","authors":"D. Whyte, P. V. Oorschot, E. Kranakis","doi":"10.1109/CSAC.2005.20","DOIUrl":"https://doi.org/10.1109/CSAC.2005.20","url":null,"abstract":"Signature-based schemes for detecting Internet worms often fail on zero-day worms, and their ability to rapidly react to new threats is typically limited by the requirement of some form of human involvement to formulate updated attack signatures. We propose an anomaly-based detection technique detailing a method to detect propagation of scanning worms within individual network cells, thus protecting internal networks from infection by internal clients. Our software implementation indicates that this technique is both accurate and rapid enough to enable automatic containment and suppression of worm propagation within a network cell. Our approach relies on an aggregate anomaly score, derived from the correlation of address resolution protocol (ARP) activity from individual network attached devices. Our preliminary analysis and prototype indicate that this technique can be used to rapidly detect zero-day worms within a very small number of scans","PeriodicalId":422994,"journal":{"name":"21st Annual Computer Security Applications Conference (ACSAC'05)","volume":"102 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2005-12-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121799583","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Text-password based authentication schemes are a popular means of authenticating users in computer systems. Standard security practices that were intended to make passwords more difficult to crack, such as requiring users to have passwords that "look random" (high entropy), have made password systems less usable and paradoxically, less secure. In this work, we address the need for enhancing the usability of existing text-password systems without necessitating any modifications to the existing password authentication infrastructure. We propose, develop and evaluate a system that automatically generates memorable mnemonics for a given password based on a text-corpus. Initial experimental results suggest that automatic mnemonic generation is a promising technique for making text-password systems more usable. Our system was able to generate mnemonics for 80.5% of six-character passwords and 62.7% of seven-character passwords containing lower-case characters (a-z), even when the text-corpus size is extremely small (1000 sentences)
{"title":"Have the cake and eat it too - infusing usability into text-password based authentication systems","authors":"S. Jeyaraman, Umut Topkara","doi":"10.1109/CSAC.2005.28","DOIUrl":"https://doi.org/10.1109/CSAC.2005.28","url":null,"abstract":"Text-password based authentication schemes are a popular means of authenticating users in computer systems. Standard security practices that were intended to make passwords more difficult to crack, such as requiring users to have passwords that \"look random\" (high entropy), have made password systems less usable and paradoxically, less secure. In this work, we address the need for enhancing the usability of existing text-password systems without necessitating any modifications to the existing password authentication infrastructure. We propose, develop and evaluate a system that automatically generates memorable mnemonics for a given password based on a text-corpus. Initial experimental results suggest that automatic mnemonic generation is a promising technique for making text-password systems more usable. Our system was able to generate mnemonics for 80.5% of six-character passwords and 62.7% of seven-character passwords containing lower-case characters (a-z), even when the text-corpus size is extremely small (1000 sentences)","PeriodicalId":422994,"journal":{"name":"21st Annual Computer Security Applications Conference (ACSAC'05)","volume":"26 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2005-12-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131205682","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
When will we be secure? Nobody knows for sure - but it cannot happen before commercial security products and services possess not only enough functionality to satisfy customers' stated needs, but also sufficient assurance of quality, reliability, safety, and appropriateness for use. Such assurances are lacking in most of today's commercial security products and services. The author discusses paths to better assurance in operating systems, applications, and hardware through better development environments, requirements definition, systems engineering, quality certification, and legal/regulatory constraints. The author also gave some examples
{"title":"We need assurance! [assurance of computing quality, reliability, and safety]","authors":"Brian D. Snow","doi":"10.1109/CSAC.2005.63","DOIUrl":"https://doi.org/10.1109/CSAC.2005.63","url":null,"abstract":"When will we be secure? Nobody knows for sure - but it cannot happen before commercial security products and services possess not only enough functionality to satisfy customers' stated needs, but also sufficient assurance of quality, reliability, safety, and appropriateness for use. Such assurances are lacking in most of today's commercial security products and services. The author discusses paths to better assurance in operating systems, applications, and hardware through better development environments, requirements definition, systems engineering, quality certification, and legal/regulatory constraints. The author also gave some examples","PeriodicalId":422994,"journal":{"name":"21st Annual Computer Security Applications Conference (ACSAC'05)","volume":"80 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2005-12-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133793004","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Benjamin Schwarz, Hao Chen, D. Wagner, Jeremy Lin, Wei Tu, Geoff Morrison, Jacob West
Software model checking has become a popular tool for verifying programs' behavior. Recent results suggest that it is viable for finding and eradicating security bugs quickly. However, even state-of-the-art model checkers are limited in use when they report an overwhelming number of false positives, or when their lengthy running time dwarfs other software development processes. In this paper we report our experiences with software model checking for security properties on an extremely large scale - an entire Linux distribution consisting of 839 packages and 60 million lines of code. To date, we have discovered 108 exploitable bugs. Our results indicate that model checking can be both a feasible and integral part of the software development process
{"title":"Model checking an entire Linux distribution for security violations","authors":"Benjamin Schwarz, Hao Chen, D. Wagner, Jeremy Lin, Wei Tu, Geoff Morrison, Jacob West","doi":"10.1109/CSAC.2005.39","DOIUrl":"https://doi.org/10.1109/CSAC.2005.39","url":null,"abstract":"Software model checking has become a popular tool for verifying programs' behavior. Recent results suggest that it is viable for finding and eradicating security bugs quickly. However, even state-of-the-art model checkers are limited in use when they report an overwhelming number of false positives, or when their lengthy running time dwarfs other software development processes. In this paper we report our experiences with software model checking for security properties on an extremely large scale - an entire Linux distribution consisting of 839 packages and 60 million lines of code. To date, we have discovered 108 exploitable bugs. Our results indicate that model checking can be both a feasible and integral part of the software development process","PeriodicalId":422994,"journal":{"name":"21st Annual Computer Security Applications Conference (ACSAC'05)","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2005-12-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129824430","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}