Security architecture is your blueprint for keeping your company network safe - a layered approach to protecting your network and digital assets, combining technology, policies, and people. Each element plays a part in keeping your network and data safe from the myriad of threats that are out there. 

Core concepts of a security architecture

Also known as layers of defense or defense in depth, a security architecture is your deliberate plan for building multiple lines of defense. Each layer has its job, and together, they create a secure environment.

Firewalls

They are your first line of defense, acting like the moat around your castle. Firewalls filter out unwanted traffic based on predetermined rules. 

For example, you might block traffic from IP addresses known for malicious activity, ensuring they never reach your internal network. This makes it harder for threats to even get a foot in the door.

Intrusion Detection Systems (IDS)

IDSs are the guards patrolling your perimeter walls. They continuously monitor the network for suspicious activities. If something strange happens—like an employee's device suddenly transmitting large amounts of data at an unusual time—the IDS alerts you . This gives you a chance to investigate and take action quickly before any real harm occurs.

Data encryption

Encryption is a data protection technique of scrambling your data into ciphertext to make it unreadable to prying eyes. Encrypted data is only readable to people with the correct decryption key.

This layer is like having locks on every treasure chest inside the castle. Even if someone manages to get past the moat and walls, they still can’t access the treasure without the right keys. 

For example, when you send sensitive data such as customer information or financial records across your network, you encrypt it. So, even if someone intercepts this data, it's useless without the decryption key.

Access controls 

Access controls ensure that even inside the castle, only certain people can enter specific rooms. Think of it as having different keys for different rooms. 

For instance, your HR team has access to employee records but can't touch the financial databases. This compartmentalization minimizes internal risks and keeps sensitive info restricted to those who need it.

Regular security audits and vulnerability assessments

These are routine inspections where you frequently check for weak spots or outdated defenses. For example, during an audit, you may find some outdated software on a few machines. 

By promptly updating these machines, you close potential entry points for cyberattacks, keeping your defenses strong and up to date.

Employee training

Your employees are your first line of defense, your human shield against bad actors. You should hold regular training sessions to keep everyone aware of the latest threats and best practices. 

Teach your staff to spot phishing emails, create strong passwords, and follow security protocols. It’s crucial because even the best technology can be undermined by human error.

Each of these layers works together to create a comprehensive security architecture. Firewalls, IDS, encryption, access controls, regular audits, and well-trained employees—all are essential components. 

When you build a robust security architecture, you are not just putting up walls; you are building a multi-layered defense system to protect your network and data from the many threats you face.

Zero trust model

Zero Trust Model means you "trust nothing and verify everything." First, you authenticate every user and device trying to access your systems. For example, an employee doesn’t just get in because they’re on the company network. 

All employees have to prove their identity through multi-factor authentication (MFA). This might mean entering a password and then verifying via a text message code or an authentication app. 

Once authenticated, you don’t give users free reign over everything. You apply the principle of least privilege. This means employees get access only to the data and applications they need to do their jobs. 

For instance, someone in marketing won’t get access to confidential HR files. Even within the marketing department, junior staff might not access sensitive campaign strategies reserved for senior managers. It's like the difference between having a key to your own office versus a master key to the entire building.

Continuous monitoring is also a huge part of the Zero Trust Model. You don’t just check credentials once at the door. You keep an eye on activity to ensure nothing fishy is going on. 

If an approved device suddenly starts behaving oddly—like accessing data at strange times or downloading unusual amounts of information—you flag it for immediate review. Think of it as having security cameras inside the building, constantly watching for suspicious actions.

How to build your security architecture

Step 1. Assess your current security posture

This means ensuring your architecture can handle all the necessary security and compliance standards. It is a health check for your network. 

You start by identifying what your network needs to be secure. For instance, you gather security and compliance requirements from various sources like industry regulations, internal policies, and previous security assessments.

Take this example: you might need to comply with GDPR if you handle customer data from the EU. This means your systems must ensure data privacy and protection. You begin by mapping out the architecture components such as servers, databases, and endpoints. Each component must meet specific security requirements to protect the data it handles.

Next, you validate these security mechanisms. For example, if you require to encrypt customer data, you ensure that every system handling this data uses strong encryption protocols. You don't just take it for granted; you test the encryption to confirm it’s robust.

You also conduct an ad-hoc review to spot any unmitigated security threats. For instance, if your review finds that an internal application is vulnerable to SQL injection attacks, you patch it right away.

Step 2. Identify your assets

This entails taking stock of everything valuable you have and figuring out what needs the most protection. You start by listing out all the critical assets. 

Think of your critical assets as anything that, if compromised, would harm your company. This can be data like customer information, financial records, or proprietary code. For instance, your customer database is an asset that holds sensitive information you must protect at all costs.

Next, consider who owns these assets. Ownership needs to be clear. For example, the marketing team might be the custodians of your customer data, while the finance team holds the keys to your financial records. Knowing who is responsible helps you ensure the right people are accountable for the security measures.

Understanding the value of these assets is another step. You assess not just their monetary worth but the impact on your business if they were compromised. 

For instance, losing customer data could lead to a significant hit on your reputation, legal repercussions, and financial losses from compensation or fines. On the other hand, losing financial records might disrupt operations but wouldn't directly affect your customers.

You also look at the interdependencies between assets. For example, your financial records might rely on a specific database server. If this server goes down, it affects your ability to access those records. Identifying these relationships helps you understand the broader impact of a potential security breach.

Assessing the sensitivity of the information stored in these assets is also crucial. You classify data based on its sensitivity—public, internal, confidential, and restricted. 

For example, your internal company policies might be classified as internal, while customer data would be marked as confidential. This classification dictates the level of security controls we apply.

You must also think about the storage and transmission of these assets. Some might be stored in databases, while others could be transmitted over email or saved on employee devices. For instance, your customer data is stored in a secure database, but employee emails might also contain snippets of this data. Ensuring you protect data no matter where it resides or how it moves is essential.

Lastly, you identify any regulatory requirements tied to these assets. For example, if you handle customer data from the EU, GDPR imposes strict controls on how you manage and protect this information. Understanding these requirements helps you stay compliant and avoid hefty fines.

By thoroughly identifying and understanding our assets, you can tailor your security measures to protect what's most valuable, keeping your company safe and secure.

Step 3. Make an inventory of your hardware and network infrastructure

The hardware and network infrastructure are the backbone of your security architecture. This is where the rubber meets the road, and your digital fortress takes shape.

First off, you have your servers. These are the heavy lifters, hosting everything from your customer databases to your internal applications. For example, your primary database server sits behind a hardware firewall, which filters out malicious traffic right at the entry point. 

You also have redundant servers in different locations. If one server goes down, another one picks up the slack, ensuring constant availability and resilience.

Then there's your network architecture. Think of it as the blueprint of your digital city. We segment our network into different zones, each with its own security protocols. 

For instance, your HR systems are in a separate network zone from your financial systems. This segmentation acts like digital barriers, making it harder for an attacker to move laterally across your network if they breach one segment.

Switches and routers are the traffic cops of your network. They direct data to where it needs to go, ensuring smooth and secure communication. You configure access control lists (ACLs) on these devices to block unauthorized traffic.

Wi-Fi networks also play a key role. You must use enterprise-grade Wi-Fi solutions that offer robust encryption and secure access protocols. Guest networks are isolated from your main corporate network. 

So, even if someone manages to get onto your guest Wi-Fi, they can't access your critical systems. This segregation helps minimize the risk from visitors or unauthorized devices.

You can also deploy Virtual Private Networks (VPNs) to secure remote access. VPNs encrypt all traffic between remote employees and your internal network. For instance, when an employee accesses your financial systems from home, the VPN ensures that their connection is secure, keeping sensitive data safe from prying eyes.

Then there is endpoint security. Each device connected to your network, whether it's a laptop, server, or even a mobile phone, has security software installed. This includes antivirus, anti-malware, and endpoint detection and response (EDR) solutions.

Lastly, we have a comprehensive patch management process. All hardware and network devices receive regular firmware updates. For instance, if a vulnerability is discovered in our router firmware, we patch it immediately, closing any doors that attackers might try to exploit.

Step 4. Threat modeling

Here you are essentially trying to anticipate where attack points could be. It's all about understanding what you are building, what could go wrong, and how to stop it. Think of it like mapping out the vulnerabilities in a medieval castle.

You start by modeling your system to get a clear picture of its structure and data flows. You can use Data Flow Diagrams (DFDs) for this purpose. 

For example, if you are developing a new customer portal, you will create a DFD to show how customer data flows through your web server, database, and payment systems. Each part of the diagram helps you spot where the data is most vulnerable.

Once you have a detailed picture, you move on to identifying threats. Here, you use the STRIDE model—Spoofing, Tampering, Repudiation, Information Disclosure, Denial of Service, and Elevation of Privileges. 

For example, considering the Spoofing threat, you might ask, “Could an attacker impersonate a legitimate user?” If a customer’s login token is vulnerable to theft, that's a spoofing threat.

In another instance, let's talk about Tampering. If your database allows unvalidated inputs, an attacker could alter key records, subverting the integrity of your system. 

Or take Information Disclosure; if you are not encrypting sensitive data in transit, a hacker could intercept and read it. Each STRIDE category gives you a roadmap to ask the right questions.

After identifying these threats, you figure out how to mitigate them. You could beef up authentication by implementing multi-factor authentication (MFA) to counter spoofing. For tampering, you might introduce input validation and regular integrity checks. When it comes to preventing information disclosure, encrypting data both at rest and in transit is crucial.

You also need to think about eliminating or transferring risks. For example, if a particular feature is too risky and not mission-critical, you might just remove it. On the other hand, you could transfer the risk by using third-party services that have more robust security controls.

Step 5. Understand your common threats and vulnerabilities

When it comes to protecting our network, understanding common threats and vulnerabilities is key. Malware, for example, is a major headache because new strains are created daily. 

For perspective, Kaspersky Lab found that new malware strains appear at the rate of 360,000 files a day. These aren’t entirely new but tweaked versions of old malware, transforming slightly to bypass antivirus programs. 

Take ransomware, for instance. It locks up your data and demands payment for the decryption key. It’s like a digital hostage situation. Then there are Trojans, hiding behind seemingly legitimate programs. They get past your defenses unnoticed, only to wreak havoc once inside. 

Worms are another type of malware. They replicate themselves and spread, often through emails, causing widespread damage.

Next, let's talk about unpatched security vulnerabilities. These are the forgotten updates on our systems. It’s all too easy to ignore those “update available” notifications, but doing so leaves your network exposed. 

Many threats exploit known vulnerabilities that could be patched if you kept up with updates. So an attacker might slip through an unpatched hole in your defenses. This is why maintaining a regular update schedule is crucial.

Hidden backdoor programs are another serious issue. These are intentional vulnerabilities left by manufacturers, sometimes for legitimate reasons like diagnostics. However, if these backdoors are undocumented, they can be exploited. 

For example, Bloomberg highlighted how Huawei routers had hidden backdoors that could have provided unauthorized access to millions of networks. It’s like leaving a spare key under the doormat—if someone finds it, they have free rein over your house.

Admin account privileges can also be dangerous. If you don’t control who gets admin-level access, you risk significant damage. It’s like giving everyone in a company a master key to every room. Ensuring only essential personnel have such privileges is a must.

Programming bugs and unknown security bugs are other vulnerabilities. Software is complex, and bugs are inevitable. When different programs interact, they can create new vulnerabilities. These bugs are often hard to predict and challenging to fix. Cybercriminals are constantly on the lookout for such flaws.

Phishing attacks rely on social engineering—tricking your employees into giving away sensitive info or downloading malware. These attacks often come as emails from trusted sources, like vendors or senior executives, asking for passwords or other sensitive information. Multifactor authentication and continuous employee training can help prevent these attacks.

IoT devices are becoming more common and pose another risk. From smart fridges to manufacturing robots, these devices can be hijacked to form botnets and carry out attacks. Many organizations don’t even realize how many IoT devices they have. Regular security audits can help you keep track of these devices and secure them properly.

Step 6. Formulate security policies and set compliance procedures

Security policies are an essential element to any security architecture that clearly outlines how you protect your valuable assets and stay on the right side of the law.

First off, you have your data protection policies. These policies dictate how you handle sensitive information. For example, your customer data protection policy may mandate that all customer information must be encrypted at rest and in transit. 

This means that whenever you are storing customer details in your database or sending them over the internet, you use strong encryption protocols. This keeps the data safe from unauthorized access.

Next, there's your access control policy. This policy ensures that only authorized personnel can access specific data and systems. This may entail following the principle of least privilege, meaning employees only get access to the information they need to do their jobs.

You also need an incident response policy that outlines the steps you take when a security incident occurs. It’s a playbook for responding to a breach—who to notify, how to contain the threat, and what procedures to follow for recovery. Following this policy ensures a swift and coordinated response, minimizing damage.

Audit and logging policies play a crucial role in your compliance efforts. You must maintain detailed logs of system activities and regularly audit these logs to detect any anomalies. 

Your policy might say that, if you notice unusual login attempts or unauthorized access to sensitive data, you investigate immediately. These logs provide a trail of activities that can be invaluable for forensic analysis in case of a security incident.

Lastly, you must have a patch management policy that ensures that all your systems and software are up-to-date. You must regularly apply patches and updates to fix security vulnerabilities. 

For example, when a new security patch is released for your operating system, your policy must mandate that you deploy it within a specified timeframe. This helps you close any security gaps and keep your defenses strong against emerging threats.

By adhering to these security policies and compliance requirements, you are not just setting rules; you are creating a structured approach to protect your network and data. It's about building a culture of security that permeates every aspect of your organization, ensuring you are always prepared to tackle the challenges of the evolving cyber landscape.

Step 7. Implement security measures

This is where you bring everything together and put your security architecture planning into action. First up, you deploy firewalls as your frontline defense. These aren't just any firewalls; they're next-generation ones capable of deep packet inspection and application-level filtering. 

Next, you set up Intrusion Detection Systems (IDS). These work like high-tech motion sensors inside your network, constantly on the lookout for unusual activity. The IDS flags anything suspicious, alerting you right away. This gives you the chance to investigate and take action before any real damage occurs.

Encryption is another critical measure. You encrypt all sensitive data, both at rest and in transit. Similarly, whenever you transmit financial records between servers, you encrypt this data to keep it secure from interceptors.

You also implement robust access controls. A good approach is to follow the principle of least privilege, ensuring employees only access what they need for their roles. 

This minimizes the risk of internal breaches. You can also use role-based access controls (RBAC) to simplify this process. Different roles come with pre-defined permissions, which makes managing access much easier and more consistent.

By carefully deploying firewalls, IDS, encryption, access controls, and conducting regular audits, along with employee training, and enforcing Zero Trust practices, you create a robust security environment. Each measure forms a comprehensive defense system tailored to your unique needs.