These are the reasons why a lot of websites now give a Checksum hash it's to compare the file to know that the file you're downloading hasn't been tampered with when you check the Checksum.
And you used Unix's cksum operation, the result would be:The quick brown fox jumps over the lazy dog
But if the message was changed to be:2382472371 44
The checksum would be:The quick brown fox jumps over the lazy doq
(Values taken directly from my school's Unix server)2539161553 44