Note that this is if you have a black-box obfuscator, and black-box obfsucators are impossible. (The proof is actually pretty simple; see [0] ("Theorem 4") for

Note that this is if you have a black-box obfuscator, and black-box obfsucators are impossible. (The proof is actually pretty simple; see [0] ("Theorem 4") for a short version.) Although, according to the article, apparently something similar is possible with an indistinguishability obfuscators; I'm not too clear on how that works. In that case, though, where you use an indistinguishability obfsucator, then yes there is the problem of having a huge program (which is probably also slower). [0] http://www.scottaaronson.com/blog/?p=392 http://www.scottaaronson.com/blog/?p=392