Alice and Bob wish to agree on a 256bit AES key They are try

Alice and Bob wish to agree on a 256-bit AES key. They are trying to decide between using 256-bit, 512-bit, or some other length DH public keys g ^x and g^y. What would be your recommendation to them?

Solution

Answer

AES key is defined for key sizes 128 bits, 192 bits and 256 bits.AES key of 128 bits is itself strong enough for most of the applications. Though 512 bit variant of AES key can be created using 128bit key block, but, for this few things will be needed to take into consideration. Why to go into so much trouble and extra cost.

So, i\'ll recommend to use 256bit AES key.