Field-level encryption (FLE) encrypts specific fields inside a record, not just the entire dataset. It allows granular protection. Only the fields that need security get encrypted, while others stay readable for queries. This is critical when storing sensitive user data such as social security numbers, payment details, or health records.
With FLE, the application, not the database, controls encryption and decryption. Data at rest is safe, and data in transit cannot be read without the right key. This removes trust from the storage layer and reduces the attack surface. Search and sort functions can still work on unencrypted fields, reducing performance impact.
Integrating FLE with Interactive Application Security Testing (IAST) changes the equation. IAST scans live applications as they run, detecting vulnerabilities in real time. When paired with FLE, it ensures encryption logic is implemented correctly and no decrypted values leak through code paths, logs, or debug output. This combination catches risks that static scans miss—like improper key handling or unprotected JSON serialization.