A computer-implemented method, comprising: for each of a plurality of client devices, receiving, by a digital component distribution system, from an application running on the client device of a user, a digital component request; identifying, by the digital component distribution system, based on the digital component request, one or more user attributes of the user; and sending, by the digital component distribution system, to the application, a digital component response comprising (i) one or more digital components and (ii) attribute data comprising the one or more user attributes of the user, wherein the application is configured to update, based on the one or more user attributes, accumulated user attribute data stored in a shared storage of the client device in response to receiving the attribute data; obtaining, by a secure aggregation system, from the shared storage of each of the plurality of client devices, the accumulated user attribute data stored in the shared storage of each client device; generating, by the secure aggregation system, an aggregated user attribute report for one or more aggregation keys using the obtained accumulated user attribute data, comprising, for each of the one or more aggregation keys, obtaining an aggregated data profile that is generated by aggregating the accumulated user attribute data from a subset of the plurality of client devices that have accessed an electronic resource or a digital component identified by the aggregation key; adjusting, by the digital component distribution system, based on the aggregated data profiles, one or more distribution parameters for distributing digital components to client devices in response to digital component requests; and distributing, by the digital component distribution system, digital components to the client devices based on the distribution parameters. for each of a plurality of client devices, receiving, by a digital component distribution system, from an application running on the client device of a user, a digital component request; identifying, by the digital component distribution system, based on the digital component request, one or more user attributes of the user; and sending, by the digital component distribution system, to the application, a digital component response comprising (i) one or more digital components and (ii) attribute data comprising the one or more user attributes of the user, wherein the application is configured to update, based on the one or more user attributes, accumulated user attribute data stored in a shared storage of the client device in response to receiving the attribute data; receiving, by a digital component distribution system, from an application running on the client device of a user, a digital component request; identifying, by the digital component distribution system, based on the digital component request, one or more user attributes of the user; and sending, by the digital component distribution system, to the application, a digital component response comprising (i) one or more digital components and (ii) attribute data comprising the one or more user attributes of the user, wherein the application is configured to update, based on the one or more user attributes, accumulated user attribute data stored in a shared storage of the client device in response to receiving the attribute data; obtaining, by a secure aggregation system, from the shared storage of each of the plurality of client devices, the accumulated user attribute data stored in the shared storage of each client device; generating, by the secure aggregation system, an aggregated user attribute report for one or more aggregation keys using the obtained accumulated user attribute data, comprising, for each of the one or more aggregation keys, obtaining an aggregated data profile that is generated by aggregating the accumulated user attribute data from a subset of the plurality of client devices that have accessed an electronic resource or a digital component identified by the aggregation key; adjusting, by the digital component distribution system, based on the aggregated data profiles, one or more distribution parameters for distributing digital components to client devices in response to digital component requests; and distributing, by the digital component distribution system, digital components to the client devices based on the distribution parameters.