In this paper, we present a privacypreserving
data-leak detection (DLD) solution to solve the issue
where a special set of sensitive data digests is used in detection.
The advantage of our method is that it enables the data owner to
safely delegate the detection operation to a semihonest provider
without revealing the sensitive data to the provider. We describe
how Internet service providers can offer their customers DLD as
an add-on service with strong privacy guarantees. The evaluation
results show that our method can support accurate detection
with very small number of false alarms under various data-leak
scenarios.