Why are there $2^{56}$ possible DES keys when there are 64 key bits? On forums I read DES has $2^{56}$ possible keys so it takes x times to brute force it with hardware x.
But there are 64 total bits of which are 8 parity bits.
But those parity bits are a 1 or 0, right?
So since you still have to calculate the parity bits and since they aren't always the same bit, doesn't this mean that you have $2^{64}$ possible DES keys?
Each 56-bit key has a unique 8-bit parity value. For this reason there are only $2^{56}$ keys.