What was Alan Turing's greatest contribution?
A conference has been held at King's College, Cambridge, to mark the centenary of Alan Turing's birth.
The mathematician and pioneering computer scientist studied at King's as both an undergraduate, and as a fellow.
BBC News caught up with speakers and delegates at the event, asking them, "What was Alan Turing's greatest contribution?".
Turing's 100th Birthday Party was organised by Jack Copeland and Mark Sprevak.
Video produced by Dougal Shaw