In numerous applications it is desirable to restrict access to plaintext data based on the recipient's location or the time. For instance, in digital cinema distribution, the distributor would like to restrict access to the location of the authorized theater and at the authorized times. Hospitals might want to restrict access to patient records to the locality of the hospital in order to better comply with regulations of the Health Insurance Portability and Accountability Act (HIPAA). Banks and financial institutions could use location-based security techniques to authenticate senders and recipients based on their locations.