>>I see - not needed imo
>>
>>And the sample code - I'd use USING instead of Close()
>
>That's what I did. :) Every new implementation of such or when I have time to adjust existing code, I am using the Using approach. This is easier, safer, cleaner and handles the memory related issues better.

And also
(1) Dispose() ( or with using) is never called in the example
SHA256Managed derives from HashAlgorithm http://msdn.microsoft.com/en-us/library/system.security.cryptography.hashalgorithm(v=vs.110).aspx

            SHA256 mySHA256 = SHA256Managed.Create();

(2) Since the property CanReuseTransform returns true http://msdn.microsoft.com/en-us/library/System.Security.Cryptography.SHA256(v=vs.110).aspx
When you need to calculate the hash for a list of files (as per the example) you can instantiate SHA256Managed only once


Same applies to MD5 or anything else deriving from HashAlgorithm