title: Where can I learn about proven methods for sharing cryptographic keys?
body: <p>Suppose that a group wants to encrypt some information, then share the encryption key among the group members in a way that requires the consensus of the group to decrypt the information. I'm interested in a variety of scenarios where the breadth of consensus ranges from unanimity to an absolute majority. A useful technique can apply to symmetric keys, private keys, or both.</p>
  
  <p>I could take a crack at rolling my own method, as I'm sure many SO members could. But for the purposes of this question, I am interested <em>only</em> in methods that have been widely published and have withstood scrutiny by expert cryptanalysts. Journal citations are good, but interpretation of academic sources are very useful too.</p>