[viraptor]

AES has a block size of 128 bits, not bytes. Using the fastest reported method, that would be 2s/block, so 16s/128bytes.

So in practice, probably that's the case - you could use homomorphic encryption for very infrequent operations on KEKs for example.

[e12e]

Well, actually I was wrong twice, so it cancels out ;-) 128 bits is enough for many things. Eg. 128 bit keys. Too little for an ECC secret key, but not by much.