Apple expands bet on cutting edge privacy technology

Differential privacy allows companies to analyze data without learning too much about users

Last year, Apple Inc. kicked off a massive experiment with new privacy technology aimed at solving an increasingly thorny problem: how to build products that understand users without snooping on their activities.

Its answer is differential privacy, a term virtually unknown outside of academic circles until a year ago. Today, other companies such as Microsoft Corp. and Uber Technologies Inc. are experimenting with the technology.

The problem differential privacy tries to tackle stems from the fact that modern data-analysis tools are capable of finding links between large databases. Privacy experts worry these tools could be used to identify people in