Systems and methods of restricting storage of data received in content requests include a data processing system obtaining a public encryption key for a resource provider. The data processing system can receive a content request from an information resource of the resource provider running on a client device. The request can include one or more key values corresponding to one or more data keys. The data processing system can identify a data key using an encryption policy specific to the resource provider, and encrypt the key value using the public encryption key. The data processing system can store the key value in encrypted form. The data processing system can generate, using the key value in encrypted form, a data report, and provide access to the data report.