“This is an unofficial list of well-known unsolved codes and ciphers. A couple of the better-known unsolved ancient historical scripts are also thrown in, since they tend to come up during any discussion of unsolved codes.”
Our friend Elonka Dunin, the crypto-queen, has put together a very nice list of unsolved codes and cyphers. Pretty fun to think of this stuff being out there in the real world, and not just in some book somewhere.
Oh Scryer, where are thou?