You could go a step further by putting the suffixes themselves into the trie and then identifying identical subtrees. If you can use gzip there's bound to be a

You could go a step further by putting the suffixes themselves into the trie and then identifying identical subtrees. If you can use gzip there's bound to be a clever way of using a suffix array as well, that might end up being better unless you can use an optimised binary format for the tree.