"We are a bunch of journalists and we share much of the information via e-mails. This has become tedious now. Hence we found out a way to share, by just having to share our private blog posts via RSS(achieved through token OAuth.) But now there is a new problem. Not all private posts are the same. I want only a specific group of people to see a specific set of feeds not all. So I started to encrypt that part of the feed required by a specific group, by a specific key, the key being shared my all those members part of that group. Since a group has the key to decrypt only a part of the feed, the information in the other part is safe. Now there seems to be a new problem, a person might be a part of two groups, that means he needs to have both the keys to decrypt it, that means the decryption is two times slower and we have to send two keys securely. Is there a way out of this problem. Can this be somehow achieved through PKI?"
(This is something I encountered while trying to solve a problem. If you are interested see http://groups.drupal.org/node/9719 )
NOTE:Imported from https://stackoverflow.com/questions/14502756/rss-feed-restricted-access