Unblocked Cross Domain Cookies
Cross Domain cookies bypassing third party cookies
Architecture
SSO domain embeds an iframe from other domain
e.g. accounts.google.com embeds an iframe from accounts.youtube.com
Then iframe exposes internal methods for setting cookies when called sends an api request to its same origin server which sets a cookie.
Whenever a SSO cookie is created it is automatically synced to all other domains iframes from multiple domains can also be embedded and cookies can also be set