title: Is there an algorithm to securely split a message into x parts requiring at least y parts to reassemble?
body: <p>Is there an algorithm to securely split a message into x parts requiring at least y parts to reassemble?  Obviously, y &lt;= x.</p>
  
  <p>An example:</p>
  
  <p>Say that I have a secret message that I only want to be read in the event of my death.  As a way to ensure this, I give a fraction of the message to ten friends.  Now, I can't guaranty that all my friends will be able to put their messages together to recover the original.  So, I construct each message fraction in such a way so as to only require any 5 friends to put their parts together to reconstruct the whole.  However, owning less than 5 parts will not give anything away about the message, except possibly the length.</p>
  
  <p>My question is, is this possible?  What algorithms might I look at to accomplish this?</p>
  
  <p>Clarification edit: The important part of this is the cryptographic strength.  An attacker should not be able to recover the message, either in whole or in part with less than y parts.</p>