I'm not an expert in this area, but since homomorphic encryption exists (though is still impractical) and obfuscators do not exist (http://www.iacr.org/archive/

I'm not an expert in this area, but since homomorphic encryption exists (though is still impractical) and obfuscators do not exist (http://www.iacr.org/archive/crypto2001/21390001.pdf http://www.iacr.org/archive/crypto2001/21390001.pdf), it follows that the former can't be used to construct the latter.