Data security strategies to safeguard sensitive data

A comprehensive approach to data security for real-time applications.

In the dynamic landscape of financial operations, prioritizing the protection of sensitive data is an imperative task. This commitment to data security is not only crucial for upholding data integrity, but also serves as the foundation for maintaining confidentiality, ensuring regulatory compliance and fortifying against unauthorized access, transaction threats and insider threats.

Data security strategies employ various methods, such as robust encryption, HTTPS/TLS, payload encryption and cryptographic keys. These combined strategies contribute to a comprehensive approach to data security, addressing various aspects of information protection.

Robust encryption measures

Robust encryption measures play a critical role at the core of any comprehensive security strategy at organizations, like Capital One. This strategic adoption is designed to ensure the safeguarding of sensitive information entrusted to our organization on a daily basis.

The crucial role of HTTPS/TLS in a data security strategy

To meet diverse operational demands, typical industry verification processes include identity checks, fraud detection and scrutiny of credit history in real-time. API calls are one way these checks can be done in real-time. To fortify the integrity and security of those data exchanges, HTTPS/TLS can be leveraged.

Key contributions of HTTPS/TLS:

  • Establishment of a secure connection: HTTPS/TLS establishes a secure and resilient connection that can be used with Third-Party Agencies, which is crucial for the seamless and trustworthy exchange of sensitive data

  • Encryption of data in transit: HTTPS/TLS ensures that data exchanged between our organization and Third-Party Agencies is encrypted, rendering it indecipherable to unauthorized entities and enhancing the confidentiality of communication.

  • Confidentiality, authentication and tamper-proofing: The protocol guarantees the confidentiality of communication, safeguards against eavesdropping or unauthorized access, authenticates the parties involved and ensures the integrity of transmitted information.

These approaches help uphold the standards of data security, proactively thwarting potential interception or manipulation attempts by malicious actors.

HTTPS/TLS: Limitations and nuances

Despite the considerable security provided by HTTPS/TLS, it is crucial to acknowledge inherent limitations. The efficacy of encryption relies on the integrity of both endpoints—the client and the server. Vulnerabilities in servers, clients' devices or network infrastructure can expose encrypted data. Additionally, while HTTPS/TLS conceals the content of communication, it does not prevent metadata analysis, potentially disclosing sensitive information.

Understanding these limitations is integral to maintaining a comprehensive perspective on security measures. HTTPS/TLS, while providing formidable protection during transit, is akin to securing a pipeline through which data flows. Intermediary entities between the source and destination may pose risks, necessitating a nuanced understanding of data security across the entire transmission and storage lifecycle. Accordingly, it is important to use other strategies with HTTPS/TLS, like payload encryption and/or cryptographic keys.

Payload encryption: Strengthening a defense-in-depth strategy

In tandem with HTTPS/TLS, payload encryption can be used to add an extra layer of security. Encrypting the entire payload strengthens the defense-in-depth strategy, addressing not only external threats but also guarding against risks posed by insiders with network or server access. This measure ensures data privacy, including metadata, enhancing user anonymity and mitigating the risk of profiling.

Cryptographic keys: Using SIG and ENC key pairs

Signature (SIG) and Encryption (ENC) key pairs can be used as a way to secure the exchange of information between an organization (sender) and a 3rd party (receivers). 

A diagram showing the multi-step process of signature and encryption key pairs and how they work between the sender and the receiver.


  • Sign the request payload with the Sender's Sign Private Key.

  • Encrypt the signed request payload with the vendor's Enc Public Key, safeguarding sensitive personal information through encryption.

  • Share the signed and encrypted payload with the vendor (e.g., a request to retrieve credit reports).


  • Decrypt the signed and encrypted payload using the vendor's Enc Private Key.

  • Verify the decrypted payload with the organization's Sign Public Key.

  • Process the request payload, generate a response payload and encrypt it with the organization's Enc Public Key.

  • Share the signed and encrypted response with the organization.


  • Decrypt the signed and encrypted response using the organization's Encrypted Private Key.

  • Verify the decrypted content with the vendor's Sign Public Key.

  • Utilize the response payload for further processing.

Assumptions for asymmetric key management: A foundation for secure data exchange

In the intricate landscape of secure data exchange between Sender and vendors, a set of foundational assumptions forms the bedrock for an effective asymmetric key management system. These assumptions are paramount to ensuring the confidentiality, integrity and seamless continuity of cryptographic processes.

Four asymmetric key pairs:

The cryptographic underpinning relies on the use of four distinct asymmetric key pairs, enhancing the robustness of the cryptographic infrastructure.

Public keys hosted by both sender and vendor:

Dual hosting of public keys by both parties ensures a trust framework essential for the integrity of the key exchange process.

Key rotation for enhanced security:

Regularly updating and rotating keys mitigates risks associated with prolonged exposure and potential compromise, aligning with industry best practices.

Automated key fetching mechanisms:

Implementing automated key fetching mechanisms streamlines and fortifies the key management process, minimizing disruptions associated with key expiry.

By embracing these assumptions, the asymmetric key management system establishes a resilient and secure foundation for data exchange between two parties.

Optimizing key management for payload encryption

To further streamline key management and enhance efficiency, an alternative pattern involves the Sender generating a secure random Payload Encryption Key (PEK). The payload is encrypted using the PEK, which is then encrypted with the Public Key provided by the vendor. Upon receipt, the vendor can decrypt the PEK using its Private Key, allowing for the decryption of the content using the PEK. The response can be encrypted with the same PEK for secure transmission back to the Sender, who can decrypt it using the original PEK. This pattern offers a pragmatic approach to minimizing key management complexities while ensuring secure data exchange between Sender and Vendor.

A diagram showing the process between a sender and a receiver using a random payload encryption key (PEK).

Real-time payload encryption challenges and limitations

In the realm of real-time data security, the implementation of payload encryption introduces notable challenges and limitations that warrant careful consideration. This encryption process, encompassing both encryption and decryption, imposes additional computational overhead atop the execution of core business logic and validations. Consequently, an impact on response time latency becomes evident, emphasizing the need for a judicious approach to striking a balance between security measures and operational efficiency.

One primary hurdle faced by developers is the intricate task of debugging payloads before decryption. The encrypted payload arrives in a scrambled form rather than a conventional text format, posing a significant challenge in comprehending and validating responses effectively. This intricacy necessitates the development of specialized debugging mechanisms, internal tools, processes and protocols to streamline the resolution process.

Moreover, the critical aspect of managing and securing encryption keys cannot be overstated. Adequate controls must be instituted to safeguard encryption keys, acknowledging their pivotal role in maintaining the integrity and confidentiality of sensitive information. The implementation of robust key management practices is imperative to mitigate the risks associated with potential unauthorized access and ensure the sustained effectiveness of the encryption framework.

Embracing a holistic data security strategy

In navigating the landscape of real-time payload encryption, a holistic approach that addresses these challenges is essential. Striking a delicate balance between enhanced security measures and the preservation of system efficiency is paramount, underscoring the importance of thoughtful implementation and meticulous key management procedures in the face of evolving cybersecurity threats. Data security encompasses a multi-faceted approach, integrating advanced encryption measures and a nuanced understanding of the intricacies involved in secure data exchange. This comprehensive strategy ensures that sensitive information remains safeguarded at every step of the transactional lifecycle.

Raja Chattopadhyay, Senior Manager, Software Engineering

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