How Can Banks Secure Big Data? Key Strategies for Protecting Customer Information

Big Data and New Security Challenges for Banks

With the rapid growth of information technology and online finance, banks are entering the big data era, extending customer and transaction data beyond internal systems to the entire internet. This brings three new data characteristics: massive volume, high value, and severe damage when leaked, creating unprecedented information security challenges.

According to Verizon’s 2014 Data Breach Investigation Report, data breaches are frequent and spreading from the internet sector to finance. The report shows that external causes (system vulnerabilities, attacks, hacking) account for over 80% of breaches, internal causes (employee misuse, stolen work computers, unmasked test data) about 15%, and partner‑related leaks about 5%.

1. Strengthening Information Security Protection Technologies

Data Encryption : Multi‑mode encryption, combining symmetric and asymmetric algorithms, offers flexible protection for diverse data and environments, making it suitable for the varied security needs of big‑data banking applications.

Access Control : Different big‑data scenarios require tailored controls—historical‑based for customer analytics, scale‑based for geographic data, and time‑based for streaming data. Beyond DAC and MAC, information‑flow‑based access control is recommended to protect data during transmission.

Security Auditing : Audits must cover every system function and user. Key audit points include system logs for intrusion analysis, minimizing unnecessary or excessive user privileges, and ensuring timely system version updates to eliminate known vulnerabilities.

2. Enhancing Sensitive Data Management

Data Loss Prevention (DLP) : Deploy DLP software to block unauthorized copying, viewing, theft, photographing, or emailing of sensitive information, and combine it with encryption so stolen data remains unreadable without DLP server authorization.

Strict Access to Sensitive Data : Grant access only to designated staff, revoke permissions immediately upon role change or departure, require approvals for off‑environment queries, and track usage to ensure alignment with approved purposes, followed by secure physical destruction.

Test Data Management : Use only anonymized or masked data for testing; when real data is essential, encrypt it during transmission. Follow the principle of minimal data extraction via secure platforms, enforce least‑privilege and real‑name policies, and consider moving testing workloads to cloud environments.

Personnel Security Awareness : Implement rigorous internal supervision, define legal liabilities for leaks, conduct regular security training, maintain confidentiality agreements covering data scope and breach responsibilities, and perform periodic assessments.

3. Managing Outsourced and External Systems

Control of On‑site Outsourced Services : Require bank‑trained supervisors to be present during any external maintenance of sensitive equipment, prohibit unsupervised copying of data, and enforce thorough data sanitization on any external devices.

Control of External Systems : Limit the duration and scope of data exchange with third‑party payment platforms or fintech partners, prohibit them from retaining sensitive information, and encourage banks to develop their own internet platforms to reduce external data exposure.

Control of Outsourced Development : Establish security testing mechanisms for outsourced code and documentation, verify source‑code consistency, and use third‑party security assessments before deployment to ensure no viruses, vulnerabilities, or suspicious code are introduced.

Conclusion

In the big‑data financial landscape, emerging technologies and business models continuously raise information security challenges for banks. By improving technical safeguards, tightening data management processes, and enforcing strict oversight of internal personnel and external partners, banks can protect customer information and funds, turning big data into a strategic advantage rather than a liability.