Proceedings 2019 Network and Distributed System Security Symposium最新文献

筛选
英文 中文
A Systematic Framework to Generate Invariants for Anomaly Detection in Industrial Control Systems 工业控制系统异常检测不变量生成的系统框架
Proceedings 2019 Network and Distributed System Security Symposium Pub Date : 2019-01-01 DOI: 10.14722/ndss.2019.23265
Cheng Feng, Venkata Reddy Palleti, A. Mathur, D. Chana
{"title":"A Systematic Framework to Generate Invariants for Anomaly Detection in Industrial Control Systems","authors":"Cheng Feng, Venkata Reddy Palleti, A. Mathur, D. Chana","doi":"10.14722/ndss.2019.23265","DOIUrl":"https://doi.org/10.14722/ndss.2019.23265","url":null,"abstract":"Industrial Control Systems (ICS) consisting of integrated hardware and software components designed to monitor and control a variety of industrial processes, are typically deployed in critical infrastructures such as water treatment plants, power grids and gas pipelines. Unlike conventional IT systems, the consequences of deviations from normal operation in ICS have the potential to cause significant physical damage to equipment, the environment and even human life. The active monitoring of invariant rules that define the physical conditions that must be maintained for the normal operation of ICS provides a means to improve the security and dependability of such systems by which early detection of anomalous system states may be achieved, allowing for timely mitigating actions – such as fault checking, system shutdown – to be taken. Generally, invariant rules are predefined by system engineers during the design phase of a given ICS build. However, this manually intensive process is costly, error-prone and, in typically complex systems, sub-optimal. In this paper we propose a novel framework that is designed to systematically generate invariant rules from information contained within ICS operational data logs, using a combination of several machine learning and data mining techniques. The effectiveness of our approach is demonstrated by experiments on two real world ICS testbeds: a water distribution system and a water treatment plant. We show that sets of invariant rules, far larger than those defined manually, can be successfully derived by our framework and that they may be used to deliver significant improvements in anomaly detection compared with the invariant rules defined by system engineers as well as the commonly used residual errorbased anomaly detection model for ICS. Keywords—industrial control systems, anomaly detection, invariant rules, machine learning.","PeriodicalId":20444,"journal":{"name":"Proceedings 2019 Network and Distributed System Security Symposium","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2019-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80997049","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}
引用次数: 85
Establishing Software Root of Trust Unconditionally 无条件建立软件信任根
Proceedings 2019 Network and Distributed System Security Symposium Pub Date : 2019-01-01 DOI: 10.14722/ndss.2019.23170
V. Gligor, Maverick Woo
{"title":"Establishing Software Root of Trust Unconditionally","authors":"V. Gligor, Maverick Woo","doi":"10.14722/ndss.2019.23170","DOIUrl":"https://doi.org/10.14722/ndss.2019.23170","url":null,"abstract":"Root-of-Trust (RoT) establishment ensures either that the state of an untrusted system contains all and only content chosen by a trusted local verifier and the system code begins execution in that state, or that the verifier discovers the existence of unaccounted for content. This ensures program booting into system states that are free of persistent malware. An adversary can no longer retain undetected control of one’s local system. We establish RoT unconditionally; i.e., without secrets, trusted hardware modules and instructions, or bounds on the adversary’s computational power. The specification of a system’s chipset and device controllers, and an external source of true random numbers, such as a commercially available quantum RNG, is all that is needed. Our system specifications are those of a concrete Word Random Access Machine (cWRAM) model – the closest computation model to a real system with a large instruction set. We define the requirements for RoT establishment and explain their differences from past attestation protocols. Then we introduce a RoT establishment protocol based on a new computation primitive with concrete (non-asymptotic) optimal space-time bounds in adversarial evaluation on the cWRAM. The new primitive is a randomized polynomial, which has kindependent uniform coefficients in a prime order field. Its collision properties are stronger than those of a k-independent (almost) universal hash function in cWRAM evaluations, and are sufficient to prove existence of malware-free states before RoT is established. Preliminary measurements show that randomizedpolynomial performance is practical on commodity hardware even for very large k. To prove the concrete optimality of randomized polynomials, we present a result of independent complexity interest: a Hornerrule program is uniquely optimal whenever the cWRAM execution space and time are simultaneously minimized.","PeriodicalId":20444,"journal":{"name":"Proceedings 2019 Network and Distributed System Security Symposium","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2019-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80421656","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}
引用次数: 18
Digital Healthcare-Associated Infection: A Case Study on the Security of a Major Multi-Campus Hospital System 数字医疗相关感染:一个大型多校区医院系统安全案例研究
Proceedings 2019 Network and Distributed System Security Symposium Pub Date : 2019-01-01 DOI: 10.14722/ndss.2019.23444
Luis Vargas, Logan Blue, Vanessa Frost, Christopher Patton, Nolen Scaife, Kevin R. B. Butler, Patrick Traynor
{"title":"Digital Healthcare-Associated Infection: A Case Study on the Security of a Major Multi-Campus Hospital System","authors":"Luis Vargas, Logan Blue, Vanessa Frost, Christopher Patton, Nolen Scaife, Kevin R. B. Butler, Patrick Traynor","doi":"10.14722/ndss.2019.23444","DOIUrl":"https://doi.org/10.14722/ndss.2019.23444","url":null,"abstract":"","PeriodicalId":20444,"journal":{"name":"Proceedings 2019 Network and Distributed System Security Symposium","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2019-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86692323","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}
引用次数: 4
One Engine To Serve 'em All: Inferring Taint Rules Without Architectural Semantics 一个服务于所有人的引擎:在没有架构语义的情况下推断污染规则
Proceedings 2019 Network and Distributed System Security Symposium Pub Date : 2019-01-01 DOI: 10.14722/ndss.2019.23339
Zheng Leong Chua, Yanhao Wang, Teodora Baluta, P. Saxena, Zhenkai Liang, Purui Su
{"title":"One Engine To Serve 'em All: Inferring Taint Rules Without Architectural Semantics","authors":"Zheng Leong Chua, Yanhao Wang, Teodora Baluta, P. Saxena, Zhenkai Liang, Purui Su","doi":"10.14722/ndss.2019.23339","DOIUrl":"https://doi.org/10.14722/ndss.2019.23339","url":null,"abstract":"Dynamic binary taint analysis has wide applications in the security analysis of commercial-off-the-shelf (COTS) binaries. One of the key challenges in dynamic binary analysis is to specify the taint rules that capture how taint information propagates for each instruction on an architecture. Most of the existing solutions specify taint rules using a deductive approach by summarizing the rules manually after analyzing the instruction semantics. Intuitively, taint propagation reflects on how an instruction input affects its output, and thus can be observed from instruction executions. In this work, we propose an inductive method for taint propagation and develop a universal taint tracking engine that is architecture-agnostic. Our taint engine, TAINTINDUCE, can learn taint rules with minimal architectural knowledge by observing the execution behavior of instructions. To measure its correctness and guide taint rule generation, we define the precise notion of soundness for bit-level taint tracking in this novel setup. In our evaluation, we show that TAINTINDUCE automatically learns rules for 4 widely used architectures: x86, x64, AArch64, and MIPS-I. It can detect vulnerabilities for 24 CVEs in 15 applications on both Linux and Windows over millions of instructions and is comparable with other mature existing tools (TEMU [51], libdft [32], Triton [42]). TAINTINDUCE can be used as a stand-alone taint engine or be used to complement existing taint engines for unhandled instructions. Further, it can be used as a cross-referencing tool to uncover bugs in taint engines, emulation implementations and ISA documentations.","PeriodicalId":20444,"journal":{"name":"Proceedings 2019 Network and Distributed System Security Symposium","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2019-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83532148","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}
引用次数: 30
Privacy Attacks to the 4G and 5G Cellular Paging Protocols Using Side Channel Information 利用侧信道信息对4G和5G蜂窝寻呼协议的隐私攻击
Proceedings 2019 Network and Distributed System Security Symposium Pub Date : 2019-01-01 DOI: 10.14722/ndss.2019.23442
Syed Rafiul Hussain, Mitziu Echeverria, Omar Chowdhury, Ninghui Li, E. Bertino
{"title":"Privacy Attacks to the 4G and 5G Cellular Paging Protocols Using Side Channel Information","authors":"Syed Rafiul Hussain, Mitziu Echeverria, Omar Chowdhury, Ninghui Li, E. Bertino","doi":"10.14722/ndss.2019.23442","DOIUrl":"https://doi.org/10.14722/ndss.2019.23442","url":null,"abstract":"—The cellular paging (broadcast) protocol strives to balance between a cellular device’s energy consumption and quality-of-service by allowing the device to only periodically poll for pending services in its idle, low-power state. For a given cellular device and serving network, the exact time periods when the device polls for services (called the paging occasion ) are fixed by design in the 4G/5G cellular protocol. In this paper, we show that the fixed nature of paging occasions can be exploited by an adversary in the vicinity of a victim to associate the victim’s soft- identity (e.g., phone number, Twitter handle) with its paging occasion, with only a modest cost, through an attack dubbed ToRPEDO . Consequently, ToRPEDO can enable an adversary to verify a victim’s coarse-grained location information, inject fabricated paging messages, and mount denial-of-service attacks. We also demonstrate that, in 4G and 5G, it is plausible for an adversary to retrieve a victim device’s persistent identity (i.e., IMSI) with a brute-force IMSI-Cracking attack while using ToRPEDO as an attack sub-step. Our further investigation on 4G paging protocol deployments also identified an implementation oversight of several network providers which enables the adversary to launch an attack, named PIERCER , for associating a victim’s phone number with its IMSI; subsequently allowing targeted user location tracking. All of our attacks have been validated and evaluated in the wild using commodity hardware and software. We finally discuss potential countermeasures against the presented attacks.","PeriodicalId":20444,"journal":{"name":"Proceedings 2019 Network and Distributed System Security Symposium","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2019-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89333859","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}
引用次数: 109
rORAM: Efficient Range ORAM with O(log2 N) Locality ORAM: O(log2n)局域的有效范围ORAM
Proceedings 2019 Network and Distributed System Security Symposium Pub Date : 2019-01-01 DOI: 10.14722/ndss.2019.23320
Anrin Chakraborti, Adam J. Aviv, Seung Geol Choi, Travis Mayberry, Daniel S. Roche, R. Sion
{"title":"rORAM: Efficient Range ORAM with O(log2 N) Locality","authors":"Anrin Chakraborti, Adam J. Aviv, Seung Geol Choi, Travis Mayberry, Daniel S. Roche, R. Sion","doi":"10.14722/ndss.2019.23320","DOIUrl":"https://doi.org/10.14722/ndss.2019.23320","url":null,"abstract":"Oblivious RAM protocols (ORAMs) allow a client to access data from an untrusted storage device without revealing to that device any information about their access pattern. Typically this is accomplished through random shuffling of the data such that the storage device cannot determine where individual blocks are located, resulting in a highly randomized access pattern. Storage devices however, are typically optimized for sequential access. A large number of random disk seeks during standard ORAM operation induce a substantial overhead. In this paper, we introduce rORAM, an ORAM specifically suited for accessing ranges of sequentially logical blocks while minimizing the number of random physical disk seeks. rORAM obtains significantly better asymptotic efficiency than prior designs (Asharov et al., ePrint 2017, Demertzis et al., CRYPTO 2018) reducing both the number of seeks and communication complexity by a multiplicative factor of O(logN). An rORAM prototype is 30-50x times faster than Path ORAM for similar range-query workloads on local HDDs, 30x faster for local SSDs, and 10x faster for network block devices. rORAM’s novel disk layout can also speed up standard ORAM constructions, e.g., resulting in a 2x faster Path ORAM variant. Importantly, experiments demonstrate suitability for real world applications – rORAM is up to 5x faster running a file server and up to 11x faster running a range-query intensive video server workloads compared to standard Path ORAM.","PeriodicalId":20444,"journal":{"name":"Proceedings 2019 Network and Distributed System Security Symposium","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2019-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"91093587","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}
引用次数: 14
Network and System Security: 13th International Conference, NSS 2019, Sapporo, Japan, December 15–18, 2019, Proceedings 网络与系统安全:第13届国际会议,NSS 2019,札幌,日本,2019年12月15日至18日,会议录
Proceedings 2019 Network and Distributed System Security Symposium Pub Date : 2019-01-01 DOI: 10.1007/978-3-030-36938-5
Joseph K. Liu, Xinyi Huang
{"title":"Network and System Security: 13th International Conference, NSS 2019, Sapporo, Japan, December 15–18, 2019, Proceedings","authors":"Joseph K. Liu, Xinyi Huang","doi":"10.1007/978-3-030-36938-5","DOIUrl":"https://doi.org/10.1007/978-3-030-36938-5","url":null,"abstract":"","PeriodicalId":20444,"journal":{"name":"Proceedings 2019 Network and Distributed System Security Symposium","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2019-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83949740","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}
引用次数: 4
Total Recall: Persistence of Passwords in Android 全面回忆:密码在Android的持久性
Proceedings 2019 Network and Distributed System Security Symposium Pub Date : 2019-01-01 DOI: 10.14722/ndss.2019.23180
Jaeho Lee, Ang Chen, D. Wallach
{"title":"Total Recall: Persistence of Passwords in Android","authors":"Jaeho Lee, Ang Chen, D. Wallach","doi":"10.14722/ndss.2019.23180","DOIUrl":"https://doi.org/10.14722/ndss.2019.23180","url":null,"abstract":"A good security practice for handling sensitive data, such as passwords, is to overwrite the data buffers with zeros once the data is no longer in use. This protects against attackers who gain a snapshot of a device’s physical memory, whether by inperson physical attacks, or by remote attacks like Meltdown and Spectre. This paper looks at unnecessary password retention in Android phones by popular apps, secure password management apps, and even the lockscreen system process. We have performed a comprehensive analysis of the Android framework and a variety of apps, and discovered that passwords can survive in a variety of locations, including UI widgets where users enter their passwords, apps that retain passwords rather than exchange them for tokens, old copies not yet reused by garbage collectors, and buffers in keyboard apps. We have developed solutions that successfully fix these problems with modest code changes.","PeriodicalId":20444,"journal":{"name":"Proceedings 2019 Network and Distributed System Security Symposium","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2019-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78976271","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}
引用次数: 3
REDQUEEN: Fuzzing with Input-to-State Correspondence REDQUEEN:输入到状态对应模糊化
Proceedings 2019 Network and Distributed System Security Symposium Pub Date : 2019-01-01 DOI: 10.14722/ndss.2019.23371
Cornelius Aschermann, Sergej Schumilo, Tim Blazytko, R. Gawlik, Thorsten Holz
{"title":"REDQUEEN: Fuzzing with Input-to-State Correspondence","authors":"Cornelius Aschermann, Sergej Schumilo, Tim Blazytko, R. Gawlik, Thorsten Holz","doi":"10.14722/ndss.2019.23371","DOIUrl":"https://doi.org/10.14722/ndss.2019.23371","url":null,"abstract":"Automated software testing based on fuzzing has experienced a revival in recent years. Especially feedback-driven fuzzing has become well-known for its ability to efficiently perform randomized testing with limited input corpora. Despite a lot of progress, two common problems are magic numbers and (nested) checksums. Computationally expensive methods such as taint tracking and symbolic execution are typically used to overcome such roadblocks. Unfortunately, such methods often require access to source code, a rather precise description of the environment (e.g., behavior of library calls or the underlying OS), or the exact semantics of the platform’s instruction set. In this paper, we introduce a lightweight, yet very effective alternative to taint tracking and symbolic execution to facilitate and optimize state-of-the-art feedback fuzzing that easily scales to large binary applications and unknown environments. We observe that during the execution of a given program, parts of the input often end up directly (i.e., nearly unmodified) in the program state. This input-to-state correspondence can be exploited to create a robust method to overcome common fuzzing roadblocks in a highly effective and efficient manner. Our prototype implementation, called REDQUEEN, is able to solve magic bytes and (nested) checksum tests automatically for a given binary executable. Additionally, we show that our techniques outperform various state-of-the-art tools on a wide variety of targets across different privilege levels (kernel-space and userland) with no platform-specific code. REDQUEEN is the first method to find more than 100% of the bugs planted in LAVA-M across all targets. Furthermore, we were able to discover 65 new bugs and obtained 16 CVEs in multiple programs and OS kernel drivers. Finally, our evaluation demonstrates that REDQUEEN is fast, widely applicable and outperforms concurrent approaches by up to three orders of magnitude.","PeriodicalId":20444,"journal":{"name":"Proceedings 2019 Network and Distributed System Security Symposium","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2019-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90503345","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}
引用次数: 241
Time Does Not Heal All Wounds: A Longitudinal Analysis of Security-Mechanism Support in Mobile Browsers 时间不能治愈所有的创伤:对移动浏览器安全机制支持的纵向分析
Proceedings 2019 Network and Distributed System Security Symposium Pub Date : 2019-01-01 DOI: 10.14722/ndss.2019.23149
Meng Luo, Pierre Laperdrix, N. Honarmand, Nick Nikiforakis
{"title":"Time Does Not Heal All Wounds: A Longitudinal Analysis of Security-Mechanism Support in Mobile Browsers","authors":"Meng Luo, Pierre Laperdrix, N. Honarmand, Nick Nikiforakis","doi":"10.14722/ndss.2019.23149","DOIUrl":"https://doi.org/10.14722/ndss.2019.23149","url":null,"abstract":"Recent market share statistics show that mobile device traffic has overtaken that of traditional desktop computers. Users spend an increasing amount of time on their smartphones and tablets, while the web continues to be the platform of choice for delivering new applications to users. In this environment, it is necessary for web applications to utilize all the tools at their disposal to protect mobile users against popular web application attacks. In this paper, we perform the first study of the support of popular web-application security mechanisms (such as the Content-Security Policy, HTTP Strict Transport Security, and Referrer Policy) across mobile browsers. We design 395 individual tests covering 8 different security mechanisms, and utilize them to evaluate the security-mechanism support in the 20 most popular browser families on Android. Moreover, by collecting and testing browser versions from the last seven years, we evaluate a total of 351 unique browser versions against the aforementioned tests, collecting more than 138K test results. By analyzing these results, we find that, although mobile browsers generally support more security mechanisms over time, not all browsers evolve in the same way. We discover popular browsers, with millions of downloads, which do not support the majority of the tested mechanisms, and identify design choices, followed by the majority of browsers, which leave hundreds of popular websites open to clickjacking attacks. Moreover, we discover the presence of multi-year vulnerability windows between the time when popular websites start utilizing a security mechanism and when mobile browsers enforce it. Our findings highlight the need for continuous security testing of mobile web browsers, as well as server-side frameworks which can adapt to the level of security that each browser can guarantee.","PeriodicalId":20444,"journal":{"name":"Proceedings 2019 Network and Distributed System Security Symposium","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2019-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89576088","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}
引用次数: 24
0
×
引用
GB/T 7714-2015
复制
MLA
复制
APA
复制
导出至
BibTeX EndNote RefMan NoteFirst NoteExpress
×
提示
您的信息不完整,为了账户安全,请先补充。
现在去补充
×
提示
您因"违规操作"
具体请查看互助需知
我知道了
×
提示
确定
请完成安全验证×
相关产品
×
本文献相关产品
联系我们:info@booksci.cn Book学术提供免费学术资源搜索服务,方便国内外学者检索中英文文献。致力于提供最便捷和优质的服务体验。 Copyright © 2023 布克学术 All rights reserved.
京ICP备2023020795号-1
ghs 京公网安备 11010802042870号
Book学术文献互助
Book学术文献互助群
群 号:481959085
Book学术官方微信