title: why is the output result of sha-256 always 256 bits and the execution time always the same?
body: <p>Why is it, that no matter the size of the input of the SHA-256 algorithm (in bitcoin mining), it always outputs a result of 256 bits? </p>
  
  <p>furthermore, how come that no matter the size of the input, the computation time is always the same?</p>