Field Hashing

Birdie supports protecting sensitive attributes before storage using cryptographic hashing.

When enabled, specific fields (e.g., national ID numbers, email, phone number, account identifiers) are transformed into irreversible hashes before being stored.

Hashing is not enabled by default. Clients must explicitly request which fields should be protected.

No key generation or key management is required from the client.


How It Works

When field hashing is enabled, Birdie applies a one-way cryptographic hash (HMAC-SHA-512) to the configured field before storage.

The original value is permanently replaced and is not stored anywhere.

The transformation is deterministic — the same input always produces the same output. This allows the hashed value to function as a stable identifier for:

  • Joins

  • Segmentation

  • Deduplication

  • Equality comparisons

Because hashing is one-way, there is no decryption process.


Irreversibility

Field hashing is irreversible by design.

Birdie does not store any information that would allow recovery of the original value.

If you need to identify the original value behind a hashed record, you must correlate it against your own database. For example, if an account identifier was hashed, you can match the hashed value with your internal records to determine which account generated a given ticket.


Enabling Field Hashing

To enable hashing, contact the Birdie team and specify which fields should be protected.

No additional setup is required from your side.


Input Formatting

Field values are hashed exactly as received.

Different representations of the same logical value will produce different hashes. For example:

To ensure consistent matching and deduplication, normalize formatting before ingestion. Recommended practices include:

  • Removing punctuation when applicable

  • Standardizing casing (e.g., lowercase emails)

  • Trimming whitespace

  • Ensuring consistent encoding (UTF-8)


Security

Hashing uses HMAC-SHA-512, a standard cryptographic construction defined in:

A secret, organization-specific pepper is used as the HMAC key. This ensures:

  • Protection against brute-force enumeration attacks

  • Isolation between organizations

  • Strong resistance even for low-entropy fields (such as national ID numbers)

The pepper is securely managed by Birdie and is never exposed.

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