Cybersecurity and Confidential Computing Architectures

This chapter introduces computing architectures suitable for applications that require an exceptional assurance of security. Critical application areas like national security systems and financial transaction processing demand this high level of protection. These systems must be resilient against a broad range of cybersecurity threats, including malicious code, covert channel attacks, and attacks enabled by physical access to the computing hardware. Topics addressed in this chapter include cybersecurity threats, encryption, digital signatures, and secure hardware and software design.

After completing this chapter, you will be able to identify the categories of cybersecurity threats a system will face and understand the security features of modern computer hardware. You will understand how to avoid security gaps in system architectures and how a secure computer architecture can help enforce security in software applications...

Technical requirements

The files for this chapter, including solutions to the exercises, are available at https://github.com/PacktPublishing/Modern-Computer-Architecture-and-Organization-Second-Edition.

Cybersecurity threats

The first step in ensuring the cybersecurity of a computer system is to understand the threats it is likely to encounter and must defend against. We can place these threats into a few broad categories and identify the key features of each category. With this information, we can design a computer system architecture with attributes that will provide an appropriate level of protection against those threats.

Unfortunately, developing a completely secure computer system is not a straightforward process. This is because new vulnerabilities are identified regularly in existing operating systems, software libraries, user applications, and web applications. It is not unusual for flaws to be identified in widely used cryptographic components such as encryption algorithms and authentication protocols. As new software products are developed, they often contain entirely new vulnerabilities that will be discovered sooner or later. Most importantly, experience shows the...

Features of secure hardware

When initiating the design of a new computer or digital device, or when revisiting the design of an existing system, it is vital that the computer architect considers security as a top-level requirement. Even the most basic decisions in the development process, such as selecting a processor model, are likely to have profound effects on the security of the resulting design. As a first step in this process, it is necessary to understand what important types of data and other technology-related information must be protected from disclosure to unauthorized individuals.

Identify what needs to be protected

Some types of information present on computers and networks that generally need to be protected against unauthorized disclosure are:

• Personal information such as passwords, social security numbers, financial data, and medical history.
• Confidential information belonging to a business including customer lists, product design data, and...

Confidential computing

Confidential computing is a recent development that aims to use cryptography and hardware-level security features to ensure data is always protected. Data can be in one of three states: at rest, in transit, or in use. Data at rest is typically located in files on a storage device. Data in transit refers to data traveling over some type of communication medium. Data in use is being actively operated on by a processor and resides in the processor’s main memory.

Confidential computing aims to ensure a comprehensive level of protection for data in all three of these possible states. Traditional security mechanisms focus on one state at a time, such as encrypting data on disk or while transferring information to and from a website. These approaches neglect the necessity to provide the same level of protection to data in use.

Securing data in use requires support from processor hardware to isolate applications from each other and to ensure the protection...

Designing for security at the architectural level

The design process for a highly secure computer system must factor in a wide range of security requirements from the very start of the process. All aspects of system design, such as processor selection and printed circuit board characteristics, must be evaluated in the light of how those components may enhance the system’s overall security, or the ways they might degrade security.

In addition to ensuring security at the lowest level of integrated circuits and printed circuit boards, it is also important to apply security design principles in a layered manner. For example, after selecting suitably secure digital components and designing a security-focused circuit layout for a digital device, it may be necessary to design a tamper-resistant case to enclose the circuit board. This case might include embedded wires intended to detect if an attacker attempts to cut or drill holes through the case and thereby gain access to the...

Ensuring security in system and application software

When developing a secure system design at the hardware level, it is important to follow through with a secure and verified design approach at all levels of the software architecture. We will next examine some of the ways that software code can introduce vulnerabilities into otherwise secure computer systems.

Common software weaknesses

This section lists several categories of software weaknesses that have traditionally caused severe security issues in operating systems, applications, and web servers. These vulnerabilities sometimes occur because software developers make assumptions about user behavior that turn out to be invalid. At other times, developers are simply unaware that particular software patterns lead to insecure designs.

Some of the techniques listed below are more likely to occur in specific programming languages, but software developers should be aware that it is possible to create insecure code in any...

Summary

This chapter introduced computing architectures suitable for uses that require an exceptional assurance of security. Critical application areas such as national security systems and financial transaction processing demand this high level of protection. These systems must be resilient against a broad range of cybersecurity threats including malicious code, covert channel attacks, and attacks enabled by physical access to the computing hardware. Topics addressed in this chapter included cybersecurity threats, encryption, digital signatures, and secure hardware and software design.

Having completed this chapter, you are able to identify many of the categories of cybersecurity threats a system will face and understand the security features of modern computer hardware. You understand some best practices for avoiding security gaps in system architectures and know how a secure computer architecture can help enforce security in software applications.

In the next chapter, we...

Exercises

1. Where supported, set up two-factor authentication for all your internet-accessible accounts containing data that you care about. This includes bank accounts, email accounts, social media, code repositories (if you are a software developer), medical services, and anything else you value. Ensure at all stages that you are using only information and software applications from trusted sources.
2. Create strong passwords for all your internet-accessible accounts containing information of value that cannot be protected by two-factor authentication. A strong password is long (15 characters or more) and includes uppercase, lowercase, numerical, and special characters (for example: ! " # $ % & ' ( ) * +). To keep track of these complicated passwords, install and use a reputable password safe application. Use care when selecting a password safe and consider its source.
3. Update the operating system and other applications and services (such as Java) on all...