Secure by Design: security from the ground up

29 April 2025

Table of contents

Secure by Design: what it is and why it matters
What is Secure by Design?
Key principles of Secure by Design
Benefits of the Secure by Design approach
Secure by Design vs. Secure by Default: the differences

Secure by Design: what it is and why it matters

Cyber security is a critical aspect of software and IT system development. However, security is often treated as an afterthought, something to be patched once vulnerabilities emerge.

This is where Secure by Design comes into play: an approach that integrates security from the very beginning of software, hardware, and infrastructure development.

In this article, we’ll explore what Secure by Design means, its key principles, the benefits it offers, and how it differs from Secure by Default.

Understanding this distinction is crucial for developers, IT administrators, and cyber security professionals to build resilient systems against cyber threats.

What is Secure by Design?

The Secure by Design concept is based on the idea that security should not be an afterthought but a fundamental principle in system development. It means building software and hardware with robust defenses already integrated, reducing the need for future fixes and minimizing security risks.

When a system is designed with this philosophy, every component is analyzed and developed with security as an essential requirement rather than an optional feature.

This proactive approach contrasts with the traditional model, where security is often added after product release through patches, updates, or additional configurations to mitigate newly discovered vulnerabilities.

Real-world examples of Secure by Design

To better understand this concept, let’s look at some practical examples of how Secure by Design is applied in software, hardware, and IT infrastructure development.

Web applications and protection against common attacks

A website or web application designed with a Secure by Design approach incorporates security measures from the development phase to protect against common attacks like SQL Injection, Cross-Site Scripting (XSS), and Cross-Site Request Forgery (CSRF).

For example:

All user input is sanitized and validated to prevent malicious data from being executed as code;

The database uses parameterized queries, preventing attackers from manipulating SQL queries to extract sensitive data;

Session cookies are set with Secure and HttpOnly flags, reducing the risk of session hijacking through XSS attacks.

Without these security features built-in from the start, applications remain vulnerable to cyberattacks that can compromise sensitive information.

Operating systems with secure default configurations

An operating system developed with Secure by Design principles ensures that critical security settings are enabled by default, without requiring users to manually configure them.

Some examples include:

Windows Defender and Windows Firewall, which are enabled by default to provide baseline protection;

Modern Linux distributions (e.g., Ubuntu, Red Hat) and macOS, which use sandboxing to isolate applications, preventing malware from spreading across the system;

Android and iOS, which automatically encrypt stored data, protecting user information if the device is lost or stolen.

In a system not designed with this philosophy, users would need to manually activate these security features, increasing the risk of misconfiguration or neglect.

Hardware with built-in security protections

Hardware can also be developed following Secure by Design principles. A key example is the Trusted Platform Module (TPM), a dedicated security chip that:

Encrypts login credentials to prevent password theft;

Protects systems from physical attacks, such as disk cloning;

Verifies system integrity at startup, preventing malicious code from executing before the OS loads.

Example
Apple’s Secure Enclave, a hardware-based security feature in iPhones and Macs that manages biometric authentication (Face ID, Touch ID) and encryption, ensuring that sensitive data remains protected even if the device is compromised.

Secure messaging Apps with end-to-end encryption

Messaging applications like Signal, WhatsApp, and Telegram (Secret Chats) apply Secure by Design principles through end-to-end encryption.

This means messages are encrypted on the sender’s device and only decrypted on the recipient’s device, preventing third parties (including the service provider) from accessing them.

If security were not integrated natively into the application, protecting user data would depend on additional software or settings, making the system less secure and more vulnerable to attacks.

Cloud computing with built-in security features

Cloud service providers also implement Secure by Design principles. Platforms like AWS, Google Cloud, and Microsoft Azure offer:

Role-Based Access Control (RBAC) to ensure that users and services only have the necessary privileges;

Automatic encryption of data at rest and in transit, reducing the risk of exposure;

Continuous threat monitoring tools, such as AWS GuardDuty or Google Chronicle, to detect suspicious activity before it escalates into an attack.

These security features are embedded directly into the cloud architecture, ensuring a strong baseline security level without requiring users to configure them manually.

Key principles of Secure by Design

A system designed according to Secure by Design principles follows a set of fundamental guidelines to ensure effective and long-lasting protection. Integrating these principles reduces the risk of vulnerabilities, protects user data, and limits damage in the event of an attack.

Let’s examine each principle in detail, with practical examples and code snippets to demonstrate their implementation.

Minimizing the attack surface

The attack surface of a system includes all the points where an attacker can attempt to exploit vulnerabilities. Reducing the attack surface means exposing only essential functionalities, avoiding unnecessary code or interfaces.

Example
A web API should expose only necessary endpoints and restrict allowed HTTP methods.

Example: limiting HTTP methods in an express (Node.js) API

const express = require('express'); 

const app = express(); 

app.use(express.json()); 

// Only allow GET requests, blocking unnecessary methods 

app.get('/api/data', (req, res) => { 

    res.json({ message: "Secure data access" }); 

}); 

// Block other HTTP methods for added security 

app.all('/api/data', (req, res) => { 

    res.status(405).send('Method Not Allowed'); 

}); 

app.listen(3000, () => console.log('Server running on port 3000'));

In this example, only GET requests are allowed for the /api/data endpoint, reducing the risk of exploits via unwanted methods.

Other best practices for attack surface reduction:

Disable unnecessary ports on servers;

Remove outdated or unused code that may introduce vulnerabilities;

Uninstall unused plugins or libraries in web applications.

Principle of least privilege

The Principle of Least Privilege (PoLP) ensures that users, processes, and applications have only the minimum permissions necessary to perform their function. If an account is compromised, this principle limits the attacker’s access to critical resources.

Example: creating a read-only user in MySQL

CREATE USER 'readonly_user'@'localhost' IDENTIFIED BY 'securepassword'; 

GRANT SELECT ON database_name.* TO 'readonly_user'@'localhost';

Here, readonly_user can only read data but cannot modify or delete it, reducing risk in case of unauthorized access.

Other implementations:

Avoid running web applications as root/admin to limit damage from potential exploits.

Use strict file permissions on Linux systems:

chmod 640 config.php  # Readable only by owner and group

Limit API token permissions to prevent excessive access.

Defense in depth

Defense in Depth involves implementing multiple layers of security to prevent a single point of failure from compromising the entire system.

For example, a web application should use multiple security measures:

Firewalls to filter malicious traffic;

TLS encryption to protect data in transit;

Multi-Factor Authentication (MFA) to prevent unauthorized logins;

Logging and monitoring to detect suspicious activities.

Example: enforcing HTTPS in express (Node.js) with TLS

const https = require('https'); 

const fs = require('fs'); 

const express = require('express'); 

const app = express(); 

// Load TLS certificate 

const options = { 

    key: fs.readFileSync('server-key.pem'), 

    cert: fs.readFileSync('server-cert.pem') 

}; 

app.get('/', (req, res) => { 

    res.send('Secure connection with TLS'); 

}); 

// Start HTTPS server 

https.createServer(options, app).listen(443, () => { 

    console.log('Secure server running on port 443'); 

});

This code ensures that communications between client and server are encrypted with TLS, protecting data from eavesdropping.

Fail securely (safe failure management)

A secure system must fail in a secure manner, avoiding exposure of sensitive information or leaving security gaps.

Common issues include visible stack traces, detailed error messages, or default fail-open configurations, which can reveal critical system details to attackers.

Example: secure error handling in a Node.js Web App

app.use((err, req, res, next) => { 

    console.error(err); // Log error details for administrators 

    res.status(500).send("Something went wrong, please try again later."); // Generic error message 

});

This ensures that error details are not exposed to users, preventing attackers from gaining system insights.

Best practices for secure failure management

Disable detailed error messages in production:

ini_set('display_errors', 0); 

ini_set('log_errors', 1); 

error_log("An error occurred");

Implement rollback mechanisms to maintain database consistency in case of errors.

Use secure retry policies to prevent brute-force login attempts.

Secure defaults (Secure by Default)

A secure system should be secure out of the box, requiring no advanced configuration by users.

Example: secure default configuration for MongoDB

security: 

  authorization: "enabled"  # Enable authentication 

  enableEncryption: true     # Encrypt data at rest 

net: 

  bindIp: 127.0.0.1          # Restrict remote access by default

These settings ensure MongoDB is secure upon installation, without requiring manual intervention.

Other examples of protection by default:

Strong password policies enabled by default for authentication systems;

Session timeouts to prevent hijacking attacks;

Disabling unnecessary services to reduce the attack surface.

Benefits of the Secure by Design approach

Adopting a Secure by Design model brings significant advantages, both in terms of security and operational efficiency.

A system built with security as a fundamental element from the start not only reduces cyber risks but also lowers the costs and time required for long-term security management. Let’s explore the key benefits in detail.

Stronger resistance to cyberattacks

A system designed according to Secure by Design principles is inherently more difficult to compromise because security measures are built-in from the start rather than added later.

A clear example is online banking applications, which implement end-to-end encryption and multi-factor authentication (MFA) from the initial development phase.

Even if an attacker steals login credentials, additional security layers—such as one-time passcodes (OTPs) or biometric verification—make unauthorized access significantly more difficult.

Another example is modern operating systems, like Windows 11 and macOS, which come with built-in security features such as memory integrity protection and automatic file encryption. This reduces the success rate of malware exploits and unauthorized access attempts.

Lower security costs

Implementing security from the design phase is far more cost-effective than fixing vulnerabilities after a product or system has been released. Every vulnerability discovered post-launch leads to:

Development and patch deployment costs;

Potential service disruptions due to urgent security updates;

Reputational damage if the vulnerability is exploited publicly.

A prime example is the Equifax data breach in 2017. A known vulnerability in Apache Struts had been left unpatched for months, leading to the exposure of 147 million customer records.

The total cost of the breach—including lawsuits, fines, and mitigation measures—was estimated at nearly $2 billion.

In contrast, companies like Google and Microsoft have embedded Secure by Design principles into their cloud services, automating vulnerability detection and mitigation, significantly reducing post-release security management costs.

Easier regulatory compliance

Many cyber security regulations and legal frameworks align with Secure by Design principles. Organizations that follow this approach can achieve compliance more easily, avoiding penalties and improving data protection.

Some key regulations that require security-by-design measures include:

GDPR (General Data Protection Regulation – EU): Mandates that data security is integrated from the system design phase (Privacy by Design, a concept closely related to Secure by Design).

NIST Cyber security Framework (USA): Recommends advanced protection strategies for IT systems and critical infrastructure.

ISO/IEC 27001: An international standard for information security management that requires proactive risk mitigation.

Example
A company developing software for the healthcare industry must comply with HIPAA (Health Insurance Portability and Accountability Act) in the U.S. This means ensuring that patient data is protected from the initial development phase, rather than relying on security patches after deployment.

Increased user trust

Users are increasingly aware of cyber security risks and prefer products and services that offer high security levels. Companies that adopt Secure by Design not only protect their customers but also gain a competitive advantage in the market.

A notable example is Signal, a secure messaging platform. Signal has built its reputation on end-to-end encryption enabled by default, without requiring users to configure it manually.

This security-first approach has led to a significant increase in trust and adoption, particularly after rival applications faced security concerns.

In the financial sector, Apple Pay and Google Pay have gained widespread user trust because they incorporate tokenization for transactions, preventing direct credit card data exposure. This security feature has driven rapid adoption, especially compared to traditional online payment methods.

Reduced need for patches and security updates

A system developed with Secure by Design principles minimizes the need for emergency patches and frequent updates to fix security vulnerabilities. This means fewer disruptions for users and a lower risk of exploits targeting unpatched flaws.

A clear example is Linux vs. Windows. Many Linux distributions, such as Ubuntu LTS (Long Term Support), are designed with a modular architecture and strict permission models, reducing the attack surface and the need for urgent security updates.

In contrast, Windows has historically required frequent critical patches to fix kernel and network service vulnerabilities.

Another example is connected vehicles. Tesla, for instance, follows Secure by Design principles in its onboard software by limiting remote access points and using secure over-the-air (OTA) updates.

This significantly reduces the need for physical recalls due to security flaws, unlike traditional automakers who have had to recall thousands of vehicles due to vulnerabilities in their infotainment systems.

Secure by Design vs. Secure by Default: the differences

The Secure by Default concept is often confused with Secure by Design, but they are distinct approaches.

While Secure by Design focuses on integrating security at the design phase, Secure by Default ensures that a system is configured securely by default upon installation.

Example
A Secure by Default operating system might have its firewall enabled automatically, enforce strong password policies, and disable remote access by default.

However, if the system was not developed with Secure by Design principles, it may still contain inherent vulnerabilities in its code or architecture.

In essence, Secure by Default is a byproduct of Secure by Design, but it alone is not enough to guarantee robust security. A truly secure system should be both designed for security and configured securely by default.

Conclusion

Secure by Design is a fundamental strategy for improving cyber security, reducing risks, and lowering the costs associated with security vulnerabilities. Integrating security at the design stage is not just a best practice—it is a necessity to effectively combat modern cyber threats.

When combined with Secure by Default, this approach ensures that systems are not only built to be secure but also configured securely from the start.

Questions and answers

What does Secure by Design mean?
It means designing software and hardware with security integrated from the start, reducing the risk of vulnerabilities and cyberattacks.
What are the key principles of Secure by Design?
Minimizing the attack surface, least privilege, defense in depth, fail securely, and secure defaults.
What is the difference between Secure by Design and Secure by Default?
Secure by Design focuses on designing security into the system, while Secure by Default ensures secure settings from the first use.
Why is Secure by Design important?
It prevents vulnerabilities rather than fixing them later, reducing costs and improving overall security.
Does Secure by Design eliminate the need for security updates?
No, but it reduces the frequency and urgency of updates, making the system more resilient.
What are some examples of Secure by Design?
Systems with built-in multi-factor authentication, default encryption, and protections against common cyber threats.
Is Secure by Design legally required?
Not always, but many security regulations, such as GDPR and the NIST Cyber security Framework, align with its principles.
How can Secure by Design be implemented in software development?
By following best practices like input validation, secure credential management, and minimizing attack surfaces.
Does Secure by Design slow down software development?
It may take longer initially, but it reduces security issues and costs in the long run.
Should all software follow Secure by Design principles?
Yes, especially applications handling sensitive data or exposed to the internet, where the risk of attacks is higher.

negg Group