Unlock Next-Level Security for Payments with AWS CloudFront Field-Level Encryption

Hi all,

Did you know, with the rise of subscription-based services according to Statista global e-commerce losses due to online payment fraud were estimated at $41 billion, with projections indicating an increase to $48 billion in 2023.

What does this tell us?

This escalating trend underscores the critical need for robust security measures in payment processing systems and whilst this is a top priority field-level encryption is necessary to protect sensitive data.

In this post you will learn the importance of securing sensitive data with Field-Level Encryption, its advantages, and actionable steps for implementation, use cases and its limitations.

Let’s consider traditional methods for contextual purpose. What makes edge encryption different?

Edge Encryption vs. Traditional Methods

Traditional encryption occurs at the backend, leaving data vulnerable during transit. Edge encryption locks down sensitive information at the very first touchpoint, minimising risk.

Imagine trusting your customers’ payment details to a system that leaves them exposed—your reputation would take a hit faster than you could say “data breach.” AWS CloudFront’s Field-Level Encryption (FLE) ensures secure payment processing while enhancing your edge computing capabilities.

What is AWS CloudFront Field-Level Encryption - FLE?

AWS CloudFront Field-Level Encryption is a security feature that encrypts sensitive data at the edge before sending it to your backend servers.

Unlike traditional TLS, which encrypts the entire payload, FLE encrypts specific parts of the payload, such as credit card numbers, ensuring enhanced security and compliance with regulations like PCI-DSS.

Implementing solutions like AWS CloudFront’s Field-Level Encryption can play a pivotal role in safeguarding sensitive customer data.

Let’s consider why.

1. Granular Security: FLE allows for the encryption of individual sensitive fields, such as credit card numbers or personally identifiable information (PII), while leaving non-sensitive data in plaintext.

This means that even if an attacker gains access to a database, they only encounter encrypted fields, rendering the sensitive information unreadable without the proper keys.

2. Reduced Attack Surface: By encrypting only the most sensitive fields, FLE minimises the amount of data that is exposed in plaintext.

This selective encryption limits the potential points of attack, making it harder for malicious actors to exploit vulnerabilities.

3. Compliance Simplification: FLE simplifies adherence to industry regulations like PCI DSS by ensuring that sensitive data is protected at all times.

This allows businesses to focus more on their core operations without the constant worry of compliance breaches due to exposed sensitive information.

4. Client-Side Encryption: FLE often employs client-side encryption, meaning that sensitive data is encrypted before it leaves the client’s environment.

This ensures that data is never transmitted in plaintext, further protecting it from interception during transmission.

Processing payments securely is non-negotiable in today’s digital-first world. AWS CloudFront Field-Level Encryption provides a robust mechanism to encrypt sensitive data at the edge, ensuring security, compliance, and performance.

Have you thought about how FLE works?

Let’s paint a picture of how this works in payment processing:

Your web application sends a public key to the customer’s browser. The customer enters their credit card details, which are encrypted using this key.

The encrypted data is forwarded through CloudFront to your backend. Your backend decrypts the data and processes the payment. It’s like handing over a locked box to the bank, with only the bank having the key.

AWS CloudFront FLE relies on public-key encryption. Here’s a step-by-step overview:

1. Define Encryption Configuration:

Create an encryption profile using AWS KMS or an external RSA public key.

Asymmetric Encryption with RSA

FLE typically utilises RSA-based asymmetric encryption for key management.

In this method, a symmetric key (often used for encrypting the actual data) is itself encrypted using RSA.

The public key encrypts the symmetric key, which can then be safely transmitted or stored.

Only the holder of the corresponding private key can decrypt this symmetric key, allowing them to access the encrypted data.

Advantages of RSA in FLE.

• Enhanced Security: RSA adds an additional layer of security because even if an attacker intercepts the encrypted symmetric key, they cannot decrypt it without access to the private key.

• Key Management: Organisations can manage their own keys securely without relying on third-party services, reducing risks associated with external breaches.

2. Integrate with CloudFront:

Attach the encryption configuration to your CloudFront distribution.

3. Encrypt Data at the Edge:

CloudFront encrypts the specified fields in the incoming request payload using the public key.

4. Secure Backend Decryption:

Only your backend servers with the private key can decrypt and process the sensitive data.

What is the primary purpose of Field-Level Encryption FLE in payment processing?

FLE provides fine-grained encryption for sensitive data fields, such as credit card numbers or personally identifiable information (PII), to ensure they are protected at the edge and throughout their journey to the backend.

Is Field-Level Encryption PCI DSS Compliant?

Yes, it is! Encrypting sensitive fields at the edge aligns perfectly with PCI DSS requirements. It ensures payment data is encrypted in transit and at rest, reducing your compliance burden and risk exposure.

How does FLE enhance the security of sensitive payment data compared to traditional encryption methods?

Traditional encryption secures the entire payload, but FLE focuses on encrypting specific sensitive fields, reducing the attack surface and ensuring compliance with regulations.

Additionally, FLE employs RSA-based asymmetric encryption, adding an extra layer of protection.

AWS CloudFront Field-Level Encryption provides fine-grained encryption for sensitive data, making it applicable across a variety of industries and scenarios where data security is paramount. Below are key use cases:

Use Cases for AWS CloudFront Field-Level Encryption (FLE) in Payment Processing

1. E-Commerce Payment Processing

Problem: Online retailers handle sensitive payment information, such as credit card numbers and billing details, which are vulnerable to interception.

Solution: FLE encrypts specific fields like credit card numbers or CVV codes at the edge before they reach the backend systems. This ensures compliance with PCI-DSS and prevents unauthorised access.

Example: During checkout, a customer’s credit card information is encrypted at the CloudFront edge location and securely transmitted to the payment gateway.

2. Financial Services Transactions

Problem: Financial institutions handle sensitive personal and financial information, including Social Security Numbers (SSNs), account numbers, and transaction data.

Solution: FLE ensures that sensitive fields in the transaction payload are encrypted before transmission. Only authorised systems can decrypt the data.

Example: A fintech app encrypts user bank account numbers during money transfers, ensuring secure communication between clients and backend systems.

3. Healthcare Payments

Problem: Healthcare organisations handle patient payment details that need to comply with both HIPAA and PCI-DSS regulations.

Solution: FLE secures payment information (e.g., credit card details) as well as patient identifiers before transmitting them to backend services, ensuring compliance with stringent data protection requirements.

Example: A hospital encrypts patient billing data at the edge before processing payments on its backend.

4. Subscription-Based Services

Problem: SaaS platforms and streaming services often collect recurring payment details from users globally, exposing this sensitive data to potential breaches.

Solution: FLE encrypts credit card and subscription plan details at the edge, protecting data as it flows through a content delivery network (CDN) to subscription management services.

Example: A streaming service encrypts subscription payment information entered by users to ensure it is securely sent to the billing system.

5. Regulatory Compliance for Government Agencies

Problem: Government agencies often collect personally identifiable information (PII) and payment details for taxes, permits, and fees, which must comply with strict regulations.

Solution: FLE encrypts fields containing sensitive PII or payment information to ensure compliance with local and international regulations, such as GDPR.

Example: An online tax portal encrypts credit card information entered for paying taxes.

6. Gaming and Digital Goods Payments

Problem: Online gaming platforms and marketplaces handle payments for in-game purchases or digital goods, exposing payment data to risk.

Solution: FLE encrypts payment-related fields at the edge, ensuring secure processing of micro-transactions and preventing fraud.

Example: A gaming platform encrypts payment details before processing purchases for in-game items.

7. Multi-Tenant SaaS Platforms

Problem: SaaS platforms serving multiple tenants may handle tenant-specific payment data that requires isolation and encryption.

Solution: FLE ensures tenant payment data is encrypted separately and decrypted only by authorised backend systems for each tenant, minimising the risk of cross-tenant data leaks.

Example: A B2B SaaS provider encrypts each tenant’s payment information separately to maintain strict isolation.

8. Online Education Platforms

Problem: EdTech platforms collect payment data for tuition, subscriptions, or course enrolments, making them a target for attackers.

Solution: FLE encrypts sensitive fields in payment payloads before sending them to payment processing services, ensuring security during transmission.

Example: An online education platform encrypts student credit card details for subscription-based courses.

9. Travel and Booking Websites

Problem: Travel agencies and booking platforms process customer payment details, exposing them to significant security risks.

Solution: FLE encrypts payment information (e.g., credit card numbers) at the edge, ensuring it is securely processed by backend booking systems.

Example: A travel booking site encrypts credit card and billing address information during ticket purchases.

10. Cryptocurrency Transactions

Problem: Cryptocurrency exchanges handle sensitive information like wallet keys and payment methods for fiat-to-crypto transactions.Solution: FLE encrypts wallet-related data and payment details to secure the transaction flow between the client and the exchange backend.

Example: A cryptocurrency exchange encrypts users’ wallet keys and payment data before processing crypto purchases.

11. Real-Time Analytics and Ad Monetisation

Problem: Real-time bidding (RTB) and analytics platforms may collect payment data for ad purchases, requiring strong encryption for sensitive fields.

Solution: FLE secures sensitive billing and payment details in ad requests or user subscriptions before transmission.

Example: An ad monetisation platform encrypts advertiser payment information submitted through a web portal.

12. Custom Payment Gateways

Problem: Custom-built payment gateways need to ensure compliance and security for payment information flowing through them.

Solution: FLE enables the encryption of specific payment fields, such as card numbers or CVVs, while leaving other fields in plaintext for gateway-specific processing.

Example: A payment gateway provider encrypts payment fields for third-party integrations to enhance security and simplify compliance.

As mentioned above, every industry needs to be thinking about how to process sensitive data as processing payments online is a critical operation for businesses, where security and speed go hand-in-hand.

With the rise in cyber threats, payment data protection has become more significant than ever.

Let’s consider the benefit.s

Key Benefits Across Use Cases

1. Enhanced Security: Sensitive fields are encrypted at the edge, mitigating risks of data breaches.

2. Compliance: Simplifies adherence to regulatory frameworks like PCI-DSS, GDPR, and HIPAA.

3. Low Latency: Secure processing without adding significant overhead to transaction times.

4. Integration: Works seamlessly with other AWS services like Lambda@Edge and AWS KMS.

AWS CloudFront’s Field-Level Encryption (FLE) is a powerful tool that provides end-to-end encryption for sensitive data, ensuring that sensitive information such as credit card details is encrypted at the edge and remains secure throughout its journey.

Limitations to Keep in Mind

While Field-Level Encryption is powerful, it’s not a one-size-fits-all solution. Here’s what to consider:

• Complex Setup: Requires careful key management and configuration.

• Performance Impact: Encryption and decryption can add slight latency.

• Use Case Specificity: Best for sensitive fields, not large datasets.

If you think this works for you, let’s get started with AWS CloudFront Field-Level Encryption.

The prerequisites for implementing FLE on AWS CloudFront?

• An AWS account with CloudFront distributions set up.

• RSA key pair (private and public keys) generated for encryption and decryption.

• Access to backend systems capable of decrypting FLE-encrypted data.

• Proper IAM roles and policies for managing FLE configurations.

The key steps in configuring FLE for secure payment processing?

• Generate an RSA key pair and import the public key into AWS.

• Create a Field-Level Encryption configuration in CloudFront.

• Define the fields to be encrypted in the request payload.

• Attach the FLE configuration to a CloudFront distribution.

How does FLE interact with other AWS services like Lambda@Edge and AWS Key Management Service (KMS)?

Lambda@Edge can preprocess or validate requests at the edge before encryption, while AWS KMS can manage and rotate encryption keys used in FLE configurations.

What are the best practices for key management and rotation in FLE?

• Use AWS KMS for automated key management.

• Rotate encryption keys periodically to minimise risk.

• Implement IAM policies to restrict access to keys.

What are the key compliance and regulatory benefits of using FLE in payment workflows?

FLE helps businesses comply with PCI-DSS by securing sensitive payment data and limiting access to authorised backend systems. It also addresses requirements for data protection under GDPR and HIPAA.

What potential challenges can arise when implementing FLE for payment systems, and how can they be mitigated?

Challenges include increased latency, integration complexity, and key management. These can be mitigated by:

• Leveraging AWS’s global infrastructure to minimise latency.

• Testing FLE configurations thoroughly before deployment.

• Using AWS KMS for simplified key management.

How can businesses monitor and troubleshoot FLE-enabled payment workflows?

Use AWS CloudWatch to monitor CloudFront logs and set up alarms for unusual activity. Enable CloudTrail for auditing FLE configuration changes.

What role does backend decryption play in completing the payment process, and how can it be optimised?

Backend decryption ensures that encrypted payment data is deciphered securely for further processing. Optimisation includes using dedicated decryption libraries and secure environments for private key management.

Implementing FLE for Payment Processing

Step 1: Generate an RSA Key Pair

1. Use AWS KMS or OpenSSL to generate an RSA key pair

2. Import the public key into AWS Management Console for use with FLE.

Step 2: Create a Field-Level Encryption Profile

1. Open the CloudFront console.

2. Navigate to Field-Level Encryption under Security.

3. Create a new FLE profile:

• Upload the RSA public key.

• Define a name for the profile.

Step 3: Define a Field-Level Encryption Configuration

1. Create an FLE configuration in the CloudFront console.

2. Specify the fields to encrypt (e.g., creditCardNumber).

3. Attach the configuration to your CloudFront distribution behaviour.

Step 4: Integrate FLE with Your Application

1. Update your application to send sensitive data in the specified payload format.

2. Ensure the sensitive fields match those defined in the FLE configuration.

Step 5: Backend Decryption

1. Deploy your backend system to handle decryption using the RSA private key.

2. Use secure libraries (e.g., cryptography in Python) for decryption.

Step 6: Test the Setup

1. Send test requests with encrypted fields.

2. Verify successful decryption at the backend.

3. Monitor CloudFront logs for errors or anomalies.

Step 7: Enable Monitoring and Alerts

1. Use AWS CloudWatch to track FLE-related metrics.

2. Set up alarms for unexpected behaviours, such as encryption/decryption errors.

Step 8: Rotate Encryption Keys Periodically

1. Update the RSA key pair.

2. Update the public key in the FLE profile.

3. Distribute the new private key to backend systems.

Best Practices for Using FLE

• Use Key Rotation: Regularly rotate encryption keys using AWS KMS to minimise risks associated with compromised keys.

• Encrypt Minimal Data: Only encrypt fields containing sensitive data to reduce processing overhead.

• Implement IAM Policies: Restrict access to your encryption keys to authorised users and services only.

• Integrate Lambda@Edge: Use Lambda@Edge functions for additional request validation and processing at the edge.

• Enable HTTPS Everywhere: Ensure all data transmitted over the network is encrypted using HTTPS.

AWS Field-Level Encryption doesn’t work in isolation—it’s part of a robust security ecosystem. You can combine it with:

• AWS WAF: Block malicious traffic before it reaches your application.

• AWS Shield: Protect against DDoS attacks.

• AWS KMS: Manage encryption keys securely.

• SSL/TLS Encryption: Secure all data in transit.

AWS CloudFront Field-Level Encryption is a game-changer for payment processing. By encrypting sensitive data at the edge, you enhance security, build customer trust, and streamline compliance.

Final Thoughts

Field-Level Encryption is a powerful solution for securing payment workflows at the edge. By following this guide, businesses can enhance security and also ensure compliance with industry regulations.

Is this guide helpful for implementing FLE in your payment system?

Explore AWS CloudFront Field-Level Encryption today and fortify your payment processing workflows. For more insights, subscribe Sync Nimbus and never miss an update on cutting-edge cloud solutions.

What’s Your Next Move?

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