1、1安全与可信security and trusted脆弱性安全脆弱性安全 vs. 结构性安全结构性安全Vulnerability vs. Structure攻防两端如何在结构性安全环境中寻求空间Space in the structural environment2摘要Summary 脆弱性安全Vulnerability-oriented security 结构性安全Structural security 结构性安全中的脆弱性Vulnerabilities in structures 结构性威胁Structural threats3脆弱性安全Vulnerability-oriented sec
2、urity4脆弱性Vulnerabilities 弱口令 simple password 病毒 virus 操作系统漏洞 OS flaw 协议漏洞 protocol flaw 造成拒绝服务攻击的性能限制performance limitation 防火墙配置不当 bad configuration of firewalls 5面向脆弱性的安全Vulnerability-oriented security 防病毒系统 anti-virus system 漏洞扫描系统 vulnerability scanner 补丁管理系统 patch management system 入侵检测系统 IDS 防
3、拒绝服务攻击系统 anti-DoS 防火墙 Firewall 多功能安全网关 UTM 6P PS SP PC C需求驱动筐架Requirement Driven BaCaMeth需求筐架Req.BCM.来自内部From Internal来自外部From External主动引导Active体系化体系化Systematic政策性政策性Policy被动要求Passive问题型问题型Problem合规性合规性Compliance7面向脆弱性的风险管理Vulnerability-oriented risk management8国家标准中的风险管理关系图Risk management elements
4、 in Chinese standard9最精简的风险管理要素模型3-element risk management model102006 SC AwardsBest anti-malware solution Best Anti-spyware Best Anti-trojan Best Anti-virus Best Anti-worm Best Content Security Solution Best Anti-spam Best Email Content Filtering Best Email Security Best IM security Best Intellectu
5、al Property Protection Best Network Security Solution Best Wireless Security Best Enterprise Firewall Best Intrusion Detection Best Intrusion Prevention Best Desktop Firewall Best Remote Access Best VPN - SSL Best VPN - Ipsec Best Endpoint Security Solution Best Web Filtering Best Encryption Best Id
6、entity Management Solution Best Password Management Best Authentication Best Single Sign-on Best Two-Factor Solution Best Unified Threat Solution Best Integrated Security Software Best Integrated Security Appliance Best Managed Security Service Best Email Managed Service Best Network Security Manage
7、ment Best Event Management Best Computer Forensics Best Policy Management Best Security Audit Best Security Management Tool Best Vulnerability Assessment and Remediation Best Patch Management Best Vulnerability Assessment Source from: http:/ security industrial environment威胁方Threat agents厂商Provider用
8、户User12木桶原理的迷失Misleading of Cask Rule 误导 将整体结构仅仅简化为防御结构 不考虑防御纵深问题 只考虑静态的结果状态 没有成本观念 Misleading Only consider prevention structure Not consider deep prevention Only consider static state Not consider cost-effective 13结构性安全Structural security基本结构basic structure紧密结构 tight structure松散结构loose structure14
9、访问控制的RM机制Reference monitor of access control 访问控制的RM机制是非常基本的安全结构 Reference monitor of access control is a very basic security structure15RM机制有效的结构性条件Structural conditions of valid RM mechanism 三个条件 不能被绕过 不可篡改 足够小，可以被证明 3 conditions of VRM Can not be bypass Can not be tampered Be small enough, can be
10、 proved16Randomly GeneratedSymmetric Key (seed + PRNG)AlicePublickeyPrivatekeyPrivate keyPublic keyBob密钥交换过程密钥交换过程Key Exchange ProcessmessageX15/ow83h7ERH39DJ3HmessageX15/ow83h7ERH39DJ3H17紧密安全结构的代表可信计算Tight security structure Trusted Computinghttp:/www.trustedcomputinggroup.org 可信的定义 Definition of t
11、rust 可信就是，一个设备的行为是按照其预期目标和指定方式执行的Trust is the expectation that a device will behave in a particular manner for a specific purpose. 一个可信平台应当至少提供三个基本特性：保护能力、完整性测量和完整性报告A trusted platform should provide at least three basic features: protected capabilities, integrity measurement and integrity reporting
12、. (From section 4.1, TCG Architecture Overview 1.0)18TCG的基石性原理Fundamental rule of TCG 信任根就像“公理”一样，是信任的基础。在PC系统中，常常用硬件芯片实现。 Roots of trust In TCG systems roots of trust are components that must be trusted because misbehavior might not be detected. 信任链则是信任传递的机制。常常采用密码技术。 Chains of trust Transitive tru
13、st also known as “Inductive Trust”, is a process where the Root of Trust gives a trustworthy description of a second group of functions. 19一个包含TPM的PCReference PC platform containing a TCG TPM20TCG 可信平台模块TCG Trusted Platform Module (TPM) 一个可信平台常常拥有三个可信根There are commonly three Roots of Trust in a tru
14、sted platform 测量可信根 root of trust for measurement (RTM) 存储可信根 root of trust for storage (RTS) 报告可信根 root of trust for reporting (RTR)21证明协议和消息交换Attestation protocol and message exchange22TPM 存储可信根的体系结构TPM Root of Trust for Storage (RTS)23TPM 部件体系结构TPM component architecture24TCG 软件分层TCG software lay
15、ering25可信平台的生命周期The trusted platform lifecycle26可信平台上的用户认证User authentication using trusted platforms 27可信平台上的用户认证User authentication using trusted platforms28经典的四角模型The classical four corners model29四角模型的可信平台实现Detailed TP deployment architecture30TCG对于可信计算平台的划分8 categories of Trusted platform31TCG的
16、IWG和TNC的对应关系the IWG and TNC architecture32TNC体系结构TNC architecture33TNC体系结构下的消息流Message flow between components34拥有TPM的TNC体系结构The TNC architecture with the TPM35思科的自防御网络体系Ciscos self-defending network36思科的自防御网络体系Ciscos self-defending network37松散安全结构的代表框架和方案Loose security structure Framework 松散结构中的各个部
17、件关联关系，常常靠人的集成来实现The connection among the components of loose structure is always integrated by human. 松散结构常常表现为框架Framework 技术框架Technology framework 管理体系Management system ISO27001, ISO20000, etc.3839技术功能是PDR的衍生PDR can express technology framework40检测能力是松散技术结构的关联要素Detection make the loose structure ti
18、ght 攻击者不得不面对越来越多的Attackers have to face more 入侵检测 IDS 漏洞扫描 scanner 应用审计系统 Application auditing system 日志系统 log system 蜜罐 honey pot 取证系统 forensic system 监控平台 monitoring platform 等等 etc.41一个信息安全管理体系的结构Structure of a ISMS (modified ISO27001)42结构性安全中的脆弱性Vulnerabilities in structures43你对刚才阐述的结构性安全有什么感觉？W
19、hats your feeling about structural security? 复杂 complex 怀疑其完备性 concern about the completion 成本 cost 蠢人永远有 stupid guys are there 44不要被“结构性安全”给忽悠了！Do not be misled by structural security 不要被“结构性安全”给忽悠了！脆弱性安全和结构性安全并不是对立的，也不是两个发展阶段；脆弱性安全也有结构，结构性安全也有脆弱性。 Do not be misled by structural security Vulnerabil
20、ity-oriented security also has structure Structural security also has vulnerabilities45借助非技术环节来侵害技术结构Find vulnerabilities from non-technology partsRandomly GeneratedSymmetric Key (seed + PRNG)AlicePublickeyPrivatekeyPrivate keyPublic keyBob46借助非技术环节来侵害技术结构Find vulnerabilities from non-technology par
21、tsRandomly GeneratedSymmetric Key (seed + PRNG)AlicePublickeyPrivatekeyPrivate keyPublic keyBobPrivate keyPublic keyCarl线路的透明插入，可以完成对于加密通信的嗅探攻击47借助非技术环节来侵害技术结构Find vulnerabilities from non-technology partsRandomly GeneratedSymmetric Key (seed + PRNG)AlicePublickeyPrivatekeyPrivate keyPublic keyBobPr
22、ivate keyPublic keyCarl48结构性安全的局限性Limitation of structural security 结构是在环境中的、有边界的environment and boundary49在生命周期中寻找弱点 Find vulnerabilities along the lifecycle 厂家的生产环节常常会埋有后门back doors embedded during manufacturing 没有一个系统是完美的No perfect system 50在结构的时序中寻找突破Find vulnerabilities through time sequence 以文
23、档保密系统为例Sample: Document protection system 文档的生成环节最可能存在漏洞Vulnerabilities during creating documentation51结构性安全的局限性Limitation of structural security 结构是在环境中的、有边界的environment and boundary 在不同阶段、不同人手中保持安全很困难different phases and organizations52在人性中寻找弱点Find vulnerabilities from human behavior 社交工程攻击Social
24、Engineering 隐私保护Privacy protection 自由倾向Anti-DRM 懒惰Lazy 53结构性安全的局限性Limitation of structural security 结构是在环境中的、有边界的environment and boundary 在不同阶段、不同人手中保持安全很困难different phases and organizations 人把科学变成了艺术Human transform science to art54结构本身可能就有问题Find vulnerabilities from structure itself55 对于AR/PEP/PDP的
25、伪装，可能打破整个结构every role may be spoofed 所有看似漂亮的结构，其性能和可用性问题可能会非常严重，会轻易被拒绝服务攻击击垮Most beautiful structures have performance and availability problems and may be easy to be kick down by DoS. 那么多传统攻击方式，可能有的还有效Some traditional attacks are still effective结构本身可能就有问题Find vulnerabilities from structure itself56
26、结构性安全还要继续博弈We are still in the game 怎么博弈？How to Play the game? 你了解对方的结构吗？Do you know the structure of all players? 你了解对方了解多少自己的结构吗？Do you know “how much have the other player known about your structure” ?57结构性威胁Structural threats知识、资源和原则Knowledge, Resources and Principles58知识Knowledge 寻求对于系统更深层次技术结构
27、的研究Who know lower? 寻求对于系统宏观结构的了解Who know the macro-structure better? 寻求对于具体对象的全面了解How many details do you know? 59资源Resources 从分布式拒绝服务攻击到僵尸网络，掌握具有结构和组织的攻击体Botnet is a sample of structural software organization for attacking 在时序上组成结构，非常有利于攻击Time sequence spreading is a good thinking of structural att
28、ack 60结构的一些关键字Key words of structure Business Distribution Hierarchy Time sequence Life-cycle Management Organization Regular Process Control Value 业务 分布式 层次 时序 生命周期 管理 组织 制度 过程控制 价值61流程化的结构思路Process-oriented structure62原则Principles 安全没有百分之百 No 100% Security 安全相对性的三个原则 3 security relativity rule生存原则
29、 survival rule风险原则 Risk rule保镖原则 bodyguard rule自身完备性要求Perfective requirement63总结 Conclusion 脆弱性安全Vulnerability-oriented security 结构性安全Structural security 结构性安全中的脆弱性Vulnerabilities in structures 结构性威胁Structural threats64总结：一个可以持续研究下去的课题Conclusion: A good problem to keep approaching脆弱性防御脆弱性防御V.O. defend结构性防御结构性防御Structuraldefend脆弱性攻击脆弱性攻击V.O. attack结构性攻击结构性攻击Structuralattack脆弱性和结构性 Vulnerability-oriented vs. structural攻击和防守 defend vs. attack65谢谢Thanks66
