title: Computer Science problems that are still problematic
body: <p>Aside from those mentioned in Wikipedia (<a href="http://en.wikipedia.org/wiki/Unsolved_problems_in_computer_science" rel="nofollow noreferrer">Unsolved problems in computer science</a>), what are other Computer Science problems that has yet to be solved?</p>
  
  <p>I thought about asking this question because other great minds out there might not be aware that such problems exist.</p>
  
  <p>(Set to community wiki; one CS problem per post please)</p>
  
  <p>Those that are posted in Wikipedia are:</p>
  
  <ul>
  <li><a href="http://en.wikipedia.org/wiki/P_and_NP" rel="nofollow noreferrer">P = NP?</a></li>
  <li><a href="http://en.wikipedia.org/wiki/One-way_function" rel="nofollow noreferrer">The existence of one-way functions</a></li>
  <li><a href="http://en.wikipedia.org/wiki/Church-Turing_thesis" rel="nofollow noreferrer">Formalize (axiomatize) the Church-Turing thesis so that it can be proved or disproved</a></li>
  <li>Scheduling algorithm deadlines greater than periods</li>
  </ul>