Secure network communications that limit information access

A system comprising:

• one or more processors;
• and
• one or more storage devices storing instructions that, when executed by the one or more processors, cause the one or more processor to perform operations comprising:
• determining, for a given domain, engagement by a user with content provided by the given domain for display by an application at a client device of the user;
• determining, based on the engagement by the user, to extend, for the given domain, a linkage between user identifiers for a user of the application;
• in response to determining to extend, for the given domain, the linkage between the user identifiers for the user of the application:
• obtaining one or more future domain-specific ephemeral user identifiers for the user and the given domain, wherein each future domain-specific ephemeral user identifier is a user identifier that the application will use to identify the user to the given domain during a future time period after a current time period lapses;
• generating an attestation record comprising:
• a set of data comprising payload data;
• a digital signature of the set of data;
• a current domain-specific ephemeral user identifier for the user and the given domain;
• and
• the one or more future domain-specific ephemeral user identifiers for the user and the given domain;
• and
• sending the attestation record to the given domain.

A non-transitory computer readable storage medium carrying instructions that, when executed by one or more processors, cause the one or more processors to perform operations comprising:

• determining, for a given domain, engagement by a user with content provided by the given domain for display by an application at a client device of the user;
• determining, based on the engagement by the user, to extend, for the given domain, a linkage between user identifiers for a user of the application;
• in response to determining to extend, for the given domain, the linkage between the user identifiers for the user of the application:
• obtaining one or more future domain-specific ephemeral user identifiers for the user and the given domain, wherein each future domain-specific ephemeral user identifier is a user identifier that the application will use to identify the user to the given domain during a future time period after a current time period lapses;
• generating an attestation record comprising:
• a set of data comprising payload data;
• a digital signature of the set of data;
• a current domain-specific ephemeral user identifier for the user and the given domain;
• and
• the one or more future domain-specific ephemeral user identifiers for the user and the given domain;
• and
• sending the attestation record to the given domain.