It means that if you generate a series of keys by simply incrementing a counter, your 192- and 256-bit keys will be cracked before my 128-bit key. But if you a

It means that if you generate a series of keys by simply incrementing a counter, your 192- and 256-bit keys will be cracked before my 128-bit key. But if you are generating keys that way, you should probably be more concerned about attacks against the RNG that generated the starting key.