[bansaisequoia]

Games Magazine runs cryptograms every month. They have cryptos at varying levels of difficulty, and some of them are super-tough. Tougher than anything you'll see on this site, because they aren't quotations. Someone created them to be super-tough. They also give helpful hints for solving them. In one issue, I saw a crypto that was so tough, it was composed entirely of five-letter words, and only one word had a repeated letter.