P v NP

5 Nov, 2015 510 Mathematics

Melvyn Bragg and guests discuss the problem of P versus NP, which has a bearing on online security. There is a $1,000,000 prize on offer from the Clay Mathematical Institute for the first person to come up with a complete solution. At its heart is the question “are there problems for which the answers can be checked by computers, but not found in a reasonable time?” If the answer to that is yes, then P does not equal NP. However, if all answers can be found easily as well as checked, if only we knew how, then P equals NP. The area has intrigued mathematicians and computer scientists since Alan Turing, in 1936, found that it’s impossible to decide in general whether an algorithm will run forever on some problems. Resting on P versus NP is the security of all online transactions which are currently encrypted: if it transpires that P=NP, if answers could be found as easily as checked, computers could crack passwords in moments.

Play on BBC Sounds website


  • Colva Roney-Dougal 11 episodes
    Reader in Pure Mathematics at the University of St Andrews
  • Timothy Gowers 4 episodes
    Royal Society Research Professor in Mathematics at the University of Cambridge
  • Leslie Ann Goldberg 2 episodes
    Professor of Computer Science and Fellow of St Edmund Hall, University of Oxford

Reading list

  • Quantum Computing Since Democritus
    Scott Aaronson (Cambridge University Press, 2013) Google Books →
  • In Pursuit of the Traveling Salesman: Mathematics at the Limits of Computation
    William J. Cook (Princeton University Press, 2012) Google Books →
  • The Golden Ticket: P, NP, and the Search for the Impossible
    Lance Fortnow (Princeton University Press, 2013) Google Books →
  • Out of their Minds: The Lives and Discoveries of 15 Great Computer Scientists
    Dennis Shasha (Springer, 2008) Google Books →

Related episodes

Programme ID: b06mtms8

Episode page: bbc.co.uk/programmes/b06mtms8

Auto-category: 510 (Mathematics)