>> The other key can simply be the same for every block, no need for RC4:
>>
>> K_1 xor AES(K_2, data) xor K_1
>
> Err, unless I've missed something, isn't this just the AES() bit? Those
> two XORs would cancel out...
Parenthesis fail. That should be:
K_1 xor AES(K_2, data xor K_1)
-- Jerry