Cookies represent an important element of HTTP providing state management to an otherwise stateless protocol. HTTP cookies currently in use are governed by the same origin policy that directs Web browsers to allow cookie sharing only between Web sites in the same DNS domain. As Web applications get richer, data sharing across domain boundaries becomes more important. While practical solutions to cross-domain data sharing exist, in many cases they increase complexity and cost. In this paper we propose a simple mechanism to share cookies using authorizations based on X.509 attribute and public key certificates. In addition to supporting secure cookie sharing between unrelated domains, it can be beneficial for hosts in the same domain when the currently used same origin policy is deemed too permissive, exposing cookies to leakage and spoofing.