Tokenisation & Masking
Dynamic masking, deterministic tokens, and preserving joinability without exposure.
5 to work through
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intermediate Multiple choice
A marketplace must stop storing raw phone numbers in its analytical estate. Analysts still need to join orders to support tickets by the same customer, and the company must be able to delete an individual's data on request. Which approach fits?
2 min answer -
intermediate
Customer phone numbers are replaced with vault-issued tokens at ingest, and the four services allowed to see raw values call the vault to detokenise on demand. The vault becomes slow rather than down - p99 goes from 8 ms to 4 seconds - for three hours during the evening peak. What happens across the estate, and what stops it?
3 min answer -
advanced
A communications platform must reduce the systems handling customer phone numbers and message content. Tokenisation or field-level encryption?
1 min answer -
advanced
A digital bank must reduce the systems that handle raw account numbers. What does tokenisation achieve, and what does it not?
2 min answer -
advanced
A payments gateway of the kind Razorpay operates tokenises customer mobile numbers before they reach the analytical estate, using deterministic tokens so analysts can still join orders to support tickets. Nine months later a red team reconstructs the mapping for a large share of customers without ever touching the token vault. What did the design assume, and which decision made the attack possible?
3 min answer
4 terms in this topic
Deterministic Tokenisation
Replacing a sensitive value with a stable surrogate so the same input always yields the same token, preserving joins while removing the value.
patternDynamic Data Masking
Redacting a column's value as the query returns it, based on who is asking - so one physical table serves cleared and uncleared audiences, while ever…
conceptToken Domain Entropy
The size and guessability of the value space a deterministic token is computed from, which decides whether that token is a usable pseudonym or a look…
patternTokenisation
Replacing a sensitive value with a meaningless surrogate, where the mapping back is held in a separate, tightly controlled vault.
Neighbouring topics
Data Governance & Semantics
General material on ownership, meaning, quality and control of data at enterprise scale.
Data Mesh
Domain ownership, data as a product, self-serve platform, and federated governance.
Data Products
A dataset with an owner, an interface, an SLO, and consumers who can rely on it.
Data Contracts
Producers committing to schema, semantics and freshness, and breaking builds when they do not.
Data Catalog
Discovery, ownership and technical metadata, and why catalogues go stale.
Business Glossary
Agreeing what a term means before arguing about which number is right.
Semantic Layer
Metric definitions held once and served to every tool that asks.
Master Data Management
One authoritative record for a customer or product across systems that each have their own.
Reference Data
Code lists, hierarchies and currencies — small, shared, and quietly load-bearing.
Data Quality Dimensions
Completeness, accuracy, timeliness, consistency, validity and uniqueness as testable claims.
Data Observability
Freshness, volume, schema and distribution monitoring for pipelines that fail silently.
Data Stewardship
The operating model that makes ownership a role rather than a slide.
Data Access Models
Role, attribute and purpose-based access over analytical data, and how they compose.
Row & Column-Level Security
Restricting slices of a table rather than the whole table, and where it is enforced.
Retention & Purge
Deleting from an append-only estate, and proving the deletion happened.
Data Sharing & Clean Rooms
Collaborating on data neither party may hand over, with computation as the interface.
Sensitivity Labelling
Propagating a classification through joins and derived tables so controls follow the data.
BI Governance
Dashboard sprawl, certified reports, and the number the board is allowed to see.
Self-Service vs Governed
Letting analysts move fast without four teams reporting four different revenues.