Hashtab

There is a great free hash algorithm utility available from Implbits on this site. After you install it when you right click on a file or folder, you'll see that you have the option to generate a SHA-1, SHA-256, CRC-32, or CRC-64 hash value.

If you right click on a file and instead select Properties, you'll that a new tab is added which lists MD5, SHA-1, and CRC-32 hash values, and when you click on Settings, you can select up to two dozen other hash algorithms. On the File Hashes tab you can select and copy hash values.

Get a Hash Value for a Directory with the Free Utility DirHash

You can get a free utility that will generate a hash value for a directory in Windows from the French company IDRIX. See the download page here: https://www.idrix.fr/Root/content/category/7/31/46/ . The way you use it is pretty simple. The zip file that gets downloaded contains just one file - dirhash.exe . Extract that to a folder, and then in that folder press CTRL + SHIFT, right click and choose 'Open command window here'. Then enter the command dirhash, followed by the directory you are generating a hash value for, and then end with hash function you want to use. (DirHash gives you an option between MD5, SHA1, SHA256, SHA384, and SHA512 .)

Reverse Hash Calculator

The Internet Storm Center has a very intriguing tool called the reverse hash calculator, https://isc.sans.edu/tools/reversehash.html . On yhis site you can draw upon a database of millions of MD5 and SHA-1 hash values

Hash values are supposed to be one way functions - in theory you should not be able to work backwards from a hash value to the original string. The actual text of passwords are often not stored in databases in order to guard against a possible security breach. However with the Internet Storm Center you can decipher a large number of passwords. For example if you generate a hash value (on how to do this, see the Tip of the Night for December 5, 2015) for the string:

mydogspot

. . . you get the MD5 hash value, 4b3b429797098df347b00dd8875f153b , which can be decoded on the ISC site.