3 ms·
> and how the [AES] block size is too small > The block size [of ChaCha20] is 512 bits, compared to AES’s 128 bits, making a wide variety of attacks, such as b
by nayuki 5y ago
> and how the [AES] block size is too small
> The block size [of ChaCha20] is 512 bits, compared to AES’s 128 bits, making a wide variety of attacks, such as birthday bound or PRP-PRF distinguishing attacks many orders of magnitude less practical
It's too bad the AES competition didn't accept Rijndael's option of 256-bit block size. I wonder why?
( https://en.wikipedia.org/wiki/Advanced_Encryption_Standard#cite_note-blocksize-2 https://en.wikipedia.org/wiki/Advanced_Encryption_Standard#c... )
- some_furry 5y agoIIRC, the AES competition specifically called for a 128-bit block size, citing the hardware requirements of that era. (This is an invitation to invoke Cunningham's Law if I'm misremembering.)
- tptacek 5y agoThe 16 byte block size was part of the brief for the AES competition; it was established before Rijndael was selected.