Everything we buy, from books to baked beans, has a product code printed on it. More sophisticated check-digit codes exist on official documents, bank notes and air tickets. What are they for and what do they mean? We take a look at the mathematical structure of these codes and explain their purposes. And in this age of boundless surveillance, are there enough numbers for each of us to have a serial number of our own?
Talk given by Professor John D Barrow FRS
Tagged with codebreaking mathematics gresham college john barrow
Keeping secrets is one of the earliest inventions of civilisation, and has become the science of cryptography. The World War II Enigma machine was just lots of scrambling, done in ways that could be understood in principle by a school child though it took daring and powerful computing to crack it. This lecture introduces the key ideas behind conventional cryptography, and explains why it is not good enough for modern applications such as international commerce on the Internet.
From http://www.gresham.ac.uk/event.asp?PageId=108&EventId=114
Tagged with cryptography security harold thimbleby gresham college lecture