I think you should get X3 working, instead of trying to find that key.
I'll post new keys if you guys can't. For a head start, these are samples from current version of EAC.
wow64.dll is decoded wow64.bin from update server, the other dll is the real payload which gets injected to game, and contains the key AE7AEE43215F3B442010CEE2AB647FBA