[zgs]

It's still a permutation: shuffling a deck of cards again doesn't make it any more random (apologies to Diaconis). A symmetric cipher is just a shuffle -- no more, no less. Sure, it "feels" unlikely that there would be a problem but can you prove that or prove at least some level of confidence in it?

The bottom line is just AES is good enough. Your data almost certainly isn't worth the effort involved for an attacker even if there was a substantial breakthrough against AES. If it was worth enough, there are far cheaper and easier ways to get access than breaking the crypto: https://xkcd.com/538/

Modern symmetric crypto is secure enough: any problems you hear about are not in the algorithms. Cracking crypto as seen in movies is a complete fiction, it doesn't work like that.

I suggest reading some introductory texts on cryptography to fill knowledge gaps.

[kbns]

Thank you. i will learn more about it.