1
vote
1answer
127 views

AES key/ciphertext space sizes

This is giving me a brain ache now... If I have AES-128, block is 128 bit, then every plaintext (128-bit) can be encrypted to some ciphertext that is also 128-bit. This is the block size. But: 128-bit ...
1
vote
2answers
138 views

AES Key Length vs Block Length

This answer points out that certain key and block lengths were a requirement for the AES submissions: The candidate algorithm shall be capable of supporting key-block combinations with sizes of ...
2
votes
1answer
303 views

How were the AES key and block length subsets of Rijndael selected?

My intuition tells me it's a trade off between speed and security, but how did the standardisation process select these three seemingly arbitrary key lengths (namely, AES-128, AES-192, AES-256).
27
votes
4answers
5k views

What are the practical difference between 256-bit, 192-bit, and 128-bit AES encryption?

AES has several different variants (AES-128, AES-192, AES-256), but why would I use one over another?