  Secure information retrieval is an essential task in today's highly digitised
society. In some applications, it may be necessary that user query's privacy
and database content's security are enforced. For these settings, symmetric
private information retrieval (SPIR) could be employed, but its implementation
is known to be demanding, requiring a private key-exchange network as the base
layer. Here, we report for the first time a realisation of provably-secure SPIR
supported by a quantum-secure key-exchange network. The SPIR scheme looks at
biometric security, offering secure retrieval of 582-byte fingerprint files
from a database with 800 entries. Our experimental results clearly demonstrate
the feasibility of SPIR with quantum secure communications, thereby opening up
new possibilities in secure distributed data storage and cloud computing over
the future Quantum Internet.
