AES Cpu Consumption: What's cheaper? To encrypt/decrypt 1024 bytes in AES-256 or 512 in AES-128 and 512 in AES-256

问题

I am trying to figure out if it is worth using differential privacy on some data that I need to secure.

So what is less CPU intensive? Encrypt the whole data in AES-256 or encrypt parts of it in AES-256 and other parts in AES-128.

Is the difference significant? Mixing schemes will require the generation of more keys and ivs for each different level of encryption.

Any references? Comments?

回答1:

Encrypt everything with AES-128 if you care about performance. AES-256 is not much more secure in practice, since 128-bit keys cannot be brute forced anywhere in the foreseeable future. Also see this blog post, where Bruce Schneier recommends against using AES-256.

来源：https://stackoverflow.com/questions/16899858/aes-cpu-consumption-whats-cheaper-to-encrypt-decrypt-1024-bytes-in-aes-256-or