To exchange views and discuss the "£10,000 cipher challenge" in Simon Singh's "The Code Book." The challenge was solved on October 12, 2000, by Fredrik Almgren, Gunnar Andersson, Torbjorn Granland, Lars Ivarsson and Staffan Ulfberg. This group is now redundant, but will stay open. If you are still tackling the challenge, there's a lot here to help you.

Please note that while the group is still open to membership, those joining for the purpose of spamming other members will be immediately banned.