制造业中的网络安全-4.2

本课程由纽约州立大学布法罗分校教授Shambhu J. Upadhyaya讲授。

4 保护运营技术和知识产权

4.2 可靠性与安全性

0:00

    [MUSIC] Welcome to Lesson 2. Having understood what is attack surface and how to determine attack surface in Lesson 1, and before moving on to the development of attack prevention and detection systems, let us try to understand the challenges in the development of a secure and reliable system.

欢迎学习第2课。理解了什么是攻击面和如何在第1课中确定攻击面，在继续开发之前攻击预防和检测系统，让我们试着去理解开发安全可靠的系统所面临的挑战。

0:26

    Both hardware and software redundancy are used to develop process replicas so as to make digital systems failure tolerant and dependable.This is true of any system, be it a database system or a mission critical process control system. But redundancy and security solutions are at odds with each other.

硬件和软件冗余都被用于开发过程复制品以使数字系统容错和可靠。任何系统都是如此，无论是数据库系统还是关键任务过程控制系统。但是冗余和安全解决方案是相互矛盾的。

0:48

    Methods to address this interplay between these two concepts will be illustrated in this lesson.First, we need to understand the concepts of reliability and security.In general terms, the reliability of a system or application refers to various bug fixes and updates of an application, and the technologies that result in a better functioning system with enhanced features. With this intuitive notion of reliability, let us look at the formal definition of reliability according to IEEE standards.

解决这两个概念之间相互作用的方法将被阐明在这节课中。首先，我们需要理解可靠性和安全性的概念。一般来说，系统或应用程序的可靠性是指应用程序的各种错误修复和更新，以及导致具有增强功能的更好运行系统的技术。有了这种直觉的可靠性概念，让我们看看IEEE标准对可靠性的正式定义。

1:27

    Reliability is the ability of a system or component to perform its required functions under stated conditions for a specified period of time.A reliable system works in conformity with some predefined requirements, and can perform well, the functions that were established during the design period.The security of a system or application deals with the malicious or accidental threats and vulnerabilities of a system.

可靠性是系统或组件执行其在规定的时间内，在规定的条件下所需的功能。一个可靠的系统符合一些预先定义的要求，并且能够很好地执行在设计期间建立的功能。系统或应用程序的安全性处理恶意的或系统的意外威胁和漏洞。

1:59

    Handling security starts with the determination of attack surface via threat modeling as seen in lesson one of this module. And developing solutions to prevent breaches.A formal definition of security by the IEEE standards is as follows.Security refers to the ability of a system to protect information and system resources with respect to confidentiality and integrity.A secure system is not vulnerable to intruder actions that can interfere with the information by eavesdropping, or modifying it in an evil minded way.

处理安全性从确定攻击面开始，通过威胁建模，如本模块第1课所述。以及开发防止违规的解决方案。IEEE标准对安全性的正式定义如下。安全性是指系统保护信息的能力保密性和完整性方面的系统资源。安全的系统不容易受到入侵者的干扰通过窃听或以邪恶的方式修改信息。

2:42

    Now having gone through the concept of both security and reliability, let us discuss the problems faced by designers while designing a secure and reliable system, such as a digital manufacturing application.The first and foremost distinction between reliability and security is,reliability deals with the internal functioning or updates of a system. While security deals with system threats and vulnerabilities.

现在我们已经了解了安全性和可靠性的概念，让我们讨论一下设计者在设计一个安全的可靠的系统，如数字制造应用程序。可靠性和安全性之间的首要区别是，可靠性涉及系统的内部功能或更新。而安全处理系统威胁和漏洞。

3:18

    What can be considered as parts of a single nested system. According to one interpretation in the literature, reliability on the one hand is the core of a system because it refers to core functioning and system performance. On the other hand, security can be referred to as a shell around the core whose goal is to provide some protection mechanism against the attacks coming from outside.

什么可以被认为是单个嵌套系统的一部分。根据文献中的一种解释，可靠性一方面是系统的核心，因为它涉及核心功能和系统性能。另一方面，安全性可以被看作是围绕核心的外壳，其目标是提供针对来自外部的攻击的一些保护机制。

3:50

    Without the core, clearly, there is no meaning of the shell.Reliability can be enhanced by building redundancy and replication, but redundancy doesn't help security because if one replica is compromised others can be compromised similarly.Also, from the security point of view, redundancy may give some clues to cryptanalysis which may result in a breach.

没有了核心，显然，外壳就没有了意义。可靠性可以通过建立冗余来增强复制，但是冗余对安全性没有帮助，因为如果一个副本被破坏，其他副本也可能被类似地破坏。此外，从安全角度来看，冗余可能会导致密码分析的一些线索可能会导致一个突破。

4:19

    So these two concepts are at odds with each other.Reliability of our system is of utmost importance, and therefore, if a system is not reliable, that is the system doesn't perform well. The security of the system is just irrelevant.System designers usually make a distinction between improvements that increase reliability and those that increase security. The reliability involves fixing bugs and reducing code discrepancies.

所以这两个概念是不一致的。我们系统的可靠性至关重要，因此，如果一个系统不可靠，那就是这个系统不能很好地运行。系统的安全性是无关紧要的。系统设计者通常区分以下改进增加可靠性和增加安全性。可靠性包括修复错误和减少代码差异。

4:55

    These updates can be tested by releasing a beta version of the application to the users.In case of security, it is a bit more complicated task since it involves code review for determining the attack surface.Such details cannot be shared with public due to applications privacy policy.In such cases, the developer have to test by themselves for the attack surface. But sometimes, the hackers can be more inventive and can discover unknown security flaws of the system in the field

可以通过发布应用程序的测试版来测试这些更新对用户来说。在安全的情况下，这是一个有点复杂的任务，因为它涉及代码审查，以确定攻击面。由于应用程序隐私政策，此类详细信息不能与公众共享。在这种情况下，开发人员必须自己测试攻击面。但是有时候，黑客更有创造力可以在现场发现系统的未知安全缺陷。

资料来源：

https://www.coursera.org/learn/cyber-security-manufacturing

原文始发于微信公众号（网络安全经济学）：制造业中的网络安全-4.2