# RSA: is it possible for the cube root attack to fail even if e=3?

I've came across an example where the e value is three but no matter what tool/script I try, I can't decrypt it. I'm wondering if the ciphertext and n is super super large, is it possible to crack it even if e=3?

• If one uses Textbook RSA and $e=3$ then the cube-root attack is the simple attack. Otherwise, this question is not clear about padding applied or not. Jan 14 at 14:55
• The cube root attack (for $e=3$) will always fail if the plaintext (after padding, if padding is applied) is larger than $\sqrt[3]{n}$. Jan 14 at 16:21