Which term ensures privacy by not revealing which data item is retrieved from a service?

Which term ensures privacy by not revealing which data item is retrieved from a service?

• A. Big Data
• B. Biometric Impersonation
• C. Private Information Retrieval (PIR)
• D. Cryptocurrency

Answer: (C)

Protecting what you retrieve from a service without revealing which item you asked for is about privacy-preserving data access. Private Information Retrieval is a set of techniques that lets you query a database in such a way that the service learns nothing about which data item you want. In practice, queries can be designed so that multiple servers or clever encoding hide the target item, and you combine the results to get the one item you need while the servers remain unaware of your specific request. This keeps your access patterns private and prevents the service from profiling what you’re looking up.

Other terms don’t describe this behavior: Big Data refers to large-scale datasets, not privacy of retrieval; Biometric Impersonation is about pretending to be someone using biometrics; Cryptocurrency concerns digital currency.