Hashtab extension helps to calculate file hash with different algorithms like crc32, md5, sha-1..,in terms of security u can use hashtab to check if a an application is modified(infected or cracked) or not downloaded correctly, by comparing between the hash code we found in our local file and the hash mentioned in the application's official website.

1-download hashtab and install it:
2-"the hashes" are in the file proprieties.