Securing Static Website Hosting with S3 and CloudFront: The Importance of Field Level Encryption

Introduction

In the world of static website hosting, Amazon S3 and CloudFront are a common and powerful duo. This combination allows developers and businesses to host websites at a lower cost while leveraging CloudFront’s global content delivery network (CDN) to ensure fast and reliable content delivery.

But while performance and cost-efficiency are often top-of-mind, security should never be overlooked. With cyber threats becoming increasingly sophisticated, failing to protect sensitive information can lead to data breaches, fines, and reputational damage. One key security feature to consider is Field Level Encryption in CloudFront, a lesser-known but critical security tool.

Why Security Matters for Static Websites

When using S3 and CloudFront for static website hosting, you might assume that security risks are minimal, especially if your content is static. However, many websites that appear static also handle user data, either through forms, cookies, or even metadata in the URLs. Any interaction involving personally identifiable information (PII) like email addresses, phone numbers, or credit card information is a potential target for cybercriminals.

Consider these alarming statistics:

• 61% of small and medium-sized businesses experienced a cyberattack in 2021, with web applications being a common vector for intrusion.
• 1 in 4 data breaches involve sensitive customer data, leading to a steep average cost of $4.24 million per breach, according to IBM’s 2022 Cost of a Data Breach report.

When it comes to static websites that may not have dynamic backend services, encrypting sensitive data fields becomes a crucial safeguard against such risks.

The Role of Field Level Encryption in CloudFront

Field Level Encryption in Amazon CloudFront is a security feature designed to protect sensitive information transmitted between clients (web browsers) and your backend services. This goes beyond just encrypting the entire connection with HTTPS — it allows for the encryption of specific data fields (such as form inputs) at the application layer. This ensures that sensitive information is protected from the moment it leaves the client until it reaches a trusted server, even if it passes through intermediate systems.

Key Benefits of Field Level Encryption:

1. Fine-grained Security: Encrypt only the data fields that need protection, minimizing overhead.
2. Layered Security: Combine Field Level Encryption with HTTPS for an additional layer of security.
3. Mitigation Against Man-in-the-Middle Attacks: Even if attackers intercept the data, they can’t decrypt the sensitive fields.

What Happens When You Don’t Encrypt Sensitive Fields?

Not enabling encryption, especially for sensitive fields, leaves your website vulnerable to cyberattacks such as:

• Man-in-the-Middle Attacks (MITM): Attackers can intercept and view unencrypted data as it traverses between the client and the server.
• Data Exposure: PII can be exposed and misused, leading to compliance violations (e.g., GDPR, CCPA).
• Reputation Damage: Customers are more likely to trust businesses that demonstrate robust data protection, and breaches can severely damage this trust.

For instance, if you’re hosting a contact form or accepting subscriptions via email, leaving this data unencrypted could result in its exposure while in transit.

How to Enable Field Level Encryption in CloudFront

Let’s walk through the process of enabling Field Level Encryption for your CloudFront distribution.

Step 1: Create a Field Level Encryption Profile

1. In the AWS Management Console, go to the CloudFront section.
2. Select Field-Level Encryption in the left-hand navigation pane.
3. Click Create a Field-Level Encryption Profile.
4. Specify a public key for encryption and configure the fields that need to be encrypted (e.g., email, creditCardNumber).
5. Review and save your profile.

Step 2: Apply the Encryption Profile to a CloudFront Behavior

1. Navigate to the CloudFront Distributions dashboard.
2. Select the distribution you want to secure.
3. Click on the Behaviors tab, choose the behavior (path pattern) you want to secure, and select Edit.
4. Under Field-Level Encryption Settings, choose the profile you created earlier.
5. Save the behavior settings.

Step 3: Deploy and Monitor

After making these changes, CloudFront will automatically start encrypting the specified fields in client requests. You can monitor the behavior using CloudFront’s logs and ensure proper data encryption through testing.

Conclusion

While static website hosting using Amazon S3 and CloudFront is a cost-effective and performant solution, security should not be neglected. With cyberattacks becoming increasingly prevalent, protecting sensitive user data is essential. Enabling Field Level Encryption in CloudFront provides an extra layer of security, ensuring that critical fields are encrypted, even if intercepted.

By following the steps outlined in this blog, you can safeguard your users’ data and ensure compliance with today’s stringent security standards. Remember, a small investment in security today can prevent costly breaches tomorrow.