< Collective holding of signer keys > There are protocols that allow a group of people to collectively hold a key. A message is passed down the line, each person in turn operating on it, and at the end it has been signed. In this way the board of directors can sign a message without any one person having the key. These protocols can probably be combined with a secret-sharing system, so that a message can be signed if a certain percentage of the key-share holders collaborate. This allows voting, with the object of the vote getting signed only if >50% vote for it. Taking a share away from someone is a bit of a problem. If someone needs to lose his voting privileges, you probably have to generate a new key and sign it with the old one, then revoke the old one. Mike