  The well-known benefits of cloud computing have spurred the popularity of
database service outsourcing, where one can resort to the cloud to conveniently
store and query databases. Coming with such popular trend is the threat to data
privacy, as the cloud gains access to the databases and queries which may
contain sensitive information, like medical or financial data. A large body of
work has been presented for querying encrypted databases, which has been mostly
focused on secure keyword search. In this paper, we instead focus on the
support for secure skyline query processing over encrypted outsourced
databases, where little work has been done. Skyline query is an advanced kind
of database query which is important for multi-criteria decision-making systems
and applications. We propose SecSkyline, a new system framework building on
lightweight cryptography for fast privacy-preserving skyline queries.
SecSkyline ambitiously provides strong protection for not only the content
confidentiality of the outsourced database, the query, and the result, but also
for data patterns that may incur indirect data leakages, such as dominance
relationships among data points and search access patterns. Extensive
experiments demonstrate that SecSkyline is substantially superior to the
state-of-the-art in query latency, with up to 813$\times$ improvement.
