Repeatable masking of sensitive data

The various technologies presented herein relate to enabling a value generated based upon a physical unclonable function (PUF) response to be available as needed, while also preventing exposure of the PUF to a malicious entity. A masked PUF response can be generated based upon applying a function to a combination of the PUF response and a data file (e.g., a bitstream), and the masked PUF response is forwarded to a requesting entity, rather than the PUF response. Hence, the PUF is masked from any entity requiring access to the PUF. The PUF can be located in a FPGA, wherein the data file is a bitstream pertinent to one or more configurable logic blocks included in the FPGA. A first masked PUF response generated with a first data file can have a different value to a second masked PUF response generated with a second data file.