[scharman]

I’m not a crypto geek! But, I thought the block size had to be smaller than the key size?

[Dylan16807]

There's no rule that you need to mix a raw key bit with every data bit. Block ciphers usually expand their key into a bunch of subkeys to use in different rounds, and you can stretch that expansion as far as you desire.

And if you squint, a stream cipher is just a block cipher with a stupidly large block.