Can you please tell me what should be the quality of an encryption function using a key size of 256 bits... I realized from my previous question that a simple XOR of plaintext (256 bits) with a suitable key of same size is totally unsafe, as the key can be totally recovered by a simple known plaintext attack. I was trying to implement my own cipher as a project for fun ! Thankyou everyone in advance... !
1 Answer
Block cipher design is hard.
In my opinion, the most accurate description of a quality would be "withstand public cryptanalysis for a couple of years, while there is enough public interest".