Does anybody know whether this would complicate existing implementations of session sharing via a shared cookie? For example, a site a.example.org may save a c

Does anybody know whether this would complicate existing implementations of session sharing via a shared cookie? For example, a site a.example.org may save a cookie for domain .example.org, and b.example.org would be able to read it. Site A would then be able to provide some information for Site B to consume, such as logged in state or ID. From the sounds of it, this total cookie protection feature will essentially not allow this implementation to work.