Need Graph Isomorphism Algorithm De-bunked

I thought this forum might be a good place to post, since graph
isomorphism is commonly suggested for use in cryptography.

I've written a graph isomorphism program that determines if two graphs
are isomorphic. It runs in O(N^3).

Since graph isomorphism is a long studied problem with (AFAIK) no known
polynomial time solution, my algorithm is more than likely flawed. Any
help finding the flaws would be appreciated! The web site is

http://www.billrocks.org/ideas

Thanks!

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