> ## Documentation Index > Fetch the complete documentation index at: https://docs.narrative.io/llms.txt > Use this file to discover all available pages before exploring further. # Narrative ID > Per-partner pseudonymous identifiers for privacy-safe data collaboration Data collaboration requires matching records across organizations—finding the same customer in both your database and a partner's dataset. But sharing raw identifiers creates privacy risks, and even standard hashing has limitations: if two companies hash the same email with SHA-256, they produce identical hashes that could be correlated across partnerships. Narrative ID solves this by creating partner-specific pseudonymous identifiers that enable matching without exposing underlying data or allowing cross-partner correlation. ## Why Narrative ID matters ### Beyond simple hashing Traditional pseudonymization through hashing converts identifiers into fixed outputs: ``` johndoe@gmail.com → 06a240d11cc201676da976f7b49341181fd180da37cbe40a77432c0a366c80c3 ``` This hash is the same everywhere. If Company A and Company B both hash their customer emails, they can match records—but so could any third party with access to both datasets. The hash becomes a de facto identifier. Narrative ID takes a different approach: the same identifier produces **different** encoded values for each partner. ``` johndoe@gmail.com → (encoded for Partner A) → NID_a8f3e2b1c9d4... johndoe@gmail.com → (encoded for Partner B) → NID_7c2d9e5f1a8b... ``` These two Narrative IDs represent the same person but cannot be correlated without going through Narrative's translation system. This provides an additional layer of privacy protection beyond standard pseudonymization. ### Key benefits | Aspect | Standard Hashing | Narrative ID | | -------------------------------- | --------------------------------------- | ------------------------------------------------------- | | **Cross-partner correlation** | Possible (same hash everywhere) | Prevented (per-partner encoding) | | **Translation between partners** | Not possible | Supported via Narrative platform | | **Identifier exposure risk** | Hash could leak to unauthorized parties | Encoded IDs only meaningful within their encoding space | | **Matching capability** | Direct hash comparison | Translation-based matching | *** ## How Narrative ID works ### Secure encoding methodology When a clear text identifier (such as an email address or hashed email) is encoded into a Narrative ID, the encoding process transforms it into a value that: * **Conceals the original data**: The encoded value reveals nothing about the underlying identifier * **Is deterministic within an encoding space**: The same identifier always produces the same Narrative ID for a given partner ``` Clear text identifier → Secure encoding with partner key → Narrative ID ``` ### Per-partner encoding spaces Each partner on the Narrative platform has their own **encoding space**—a unique cryptographic context for generating Narrative IDs. When an identifier is encoded for a specific partner, the result is tied to that partner's encoding space. This means: * **Partner A's Narrative ID** for `johndoe@gmail.com` differs from **Partner B's Narrative ID** for the same email * Neither partner can determine the other's Narrative ID without translation * A Narrative ID only has meaning within its encoding space ### Translation between partners Narrative's software provides the ability to translate Narrative IDs from one partner's encoding space to another. This enables secure collaboration: 1. **Partner A** encodes their customer identifiers into their encoding space 2. **Partner A** shares data with Narrative IDs (not raw identifiers) 3. **Narrative** translates the Narrative IDs to **Partner B's** encoding space 4. **Partner B** can now match against their own Narrative IDs The translation happens within the Narrative platform—either in the Narrative cloud or in a customer-hosted data plane—ensuring that clear text identifiers are never exposed during the collaboration. ```sql theme={null} -- Translate Narrative IDs from Partner A's space to Partner B's space SELECT NARRATIVE_ID_TRANSLATE(partner_a_narrative_id, 'partner_b_key_id') AS partner_b_narrative_id, other_columns FROM partner_a_data ``` *** ## Key concepts ### Encoding spaces An encoding space is the cryptographic namespace associated with a specific partner. Think of it as a private room where identifiers are transformed into Narrative IDs using that partner's unique encoding key. Key properties: * **Isolated**: Each partner's encoding space is independent * **Consistent**: The same identifier always maps to the same Narrative ID within an encoding space * **Non-transferable**: A Narrative ID from one encoding space cannot be directly used in another ### Match tables A **match table** is a pre-generated lookup table that pairs Narrative IDs with their corresponding clear text identifiers. Match tables enable partners to use Narrative IDs independently of the Narrative platform for certain workflows. Use cases for match tables: * Offline matching processes * Integration with systems that cannot connect to the Narrative platform directly * Performance optimization for high-volume lookups Match tables are generated within the secure environment and maintain the privacy guarantees of the Narrative ID system. *** ## Security considerations ### What Narrative ID protects against * **Identifier exposure**: Raw identifiers (emails, phone numbers) are never shared between partners * **Cross-partner correlation**: Without translation through Narrative, partners cannot determine if they share common records * **Unauthorized access**: Even if Narrative IDs are intercepted, they reveal nothing about the underlying individuals ### Defense in depth Narrative ID is one layer in a comprehensive security approach: * **Access controls** govern who can query and translate Narrative IDs * **Audit logging** tracks all encoding and translation operations * **Data plane isolation** keeps raw data within controlled environments ### Not a substitute for governance While Narrative ID provides strong privacy protections, organizations should still maintain: * Data sharing agreements with partners * Clear policies on what data can be collaborated on * Compliance documentation for regulatory requirements *** ## Related content Step-by-step guide to encoding and translating identifiers How hashing protects privacy in data collaboration NARRATIVE\_ID\_ENCODE and NARRATIVE\_ID\_TRANSLATE reference Platform-wide security architecture