Yes this does seem correct, although in this case, I believe that the word encryption rate is the wrong term to use.

"...an encryption rate of 6.4 million per second..." In this context, it seems that the encryption rate is actually the number of possible permutations that this password cracking program tries in order to obtain the correct password (basically the decryption rate). Yes realistically speaking, if those calculations are correct, 296,653 years is an extremely long time. However, this time also depends on the processor speed of the computer. The faster the computer, the more permutations it can try in a shorter amount of time as compared to a slower one. In addition, the workload can be distributed across several different machines, each of them working on a portion of the entire password. Hope this helped.

-Fractal

"...an encryption rate of 6.4 million per second..." In this context, it seems that the encryption rate is actually the number of possible permutations that this password cracking program tries in order to obtain the correct password (basically the decryption rate). Yes realistically speaking, if those calculations are correct, 296,653 years is an extremely long time. However, this time also depends on the processor speed of the computer. The faster the computer, the more permutations it can try in a shorter amount of time as compared to a slower one. In addition, the workload can be distributed across several different machines, each of them working on a portion of the entire password. Hope this helped.

-Fractal