GpuFitsCrypt integrates a flexible policy engine for fine-grained access control with a GPU-accelerated implementation of the AES-GCM authenticated encryption protocol for massive astronomical catalogs in FITS format. The framework implements a novel parallel tree-reduction strategy to overcome the inherently sequential Galois/Counter Mode (GCM) authentication hash (GHASH) bottleneck, achieving authenticated encryption throughput exceeding 380 MB/s suitable for petabyte-scale astronomical data. GpuFitsCrypt provides a robust mechanism for data providers to enforce access policies ensuring both confidentiality and integrity without hindering research workflows.