These days software vendors digitally sign many of their files using authenticode digital signatures. If you download a file that has been modified, has become corrupt or the download itself was not complete (few bytes missing), then the digital signature will be invalid. But in the old times, people used a simpler approach – they provided a hash (a unique number calculated from the file made available for download) along with the download links. The users then can calculate the hash of the downloaded files and match it with the ones provided by the developers on their websites – if it did not match, then download was corrupt.
The hashing technique is very useful when you are downloading large files like operating system installation images such as Windows ISO or Linux distribution ISO files. Before you install using the downloaded ISO files, you should ensure that download is complete and good. For hashing the files in Windows, you can use an open-source tool called Hashing that can calculate hashes using many different algorithms such as CRC32, MD5, SHA1, SHA256, SHA384, SHA512 and RIPEMD160.
The Hashing tool is a portable program and allows you to drag-n-drop files on its window. By default, it calculates only SHA1 and SHA256 hashes. But you can select which algorithms to use from the options. You can also choose the color schemes for the Hashing window from the options. There are also other options like using lower case, conversion of CRC32 into decimal, enable high priority etc.
The tool can also be used for comparing files and finding out whether they are identical. For this, you can drop two or more files on the Hashing window. It will calculate the hashes for these files and display them in the window. Now you can click on the Find Identicals button and it will show all the identical files grouping them together along with the various hashing algorithms used to find the identicals.
Hashing is a well designed file hashing tool that supports all the popular algorithms like as CRC32, MD5, SHA1, SHA256, SHA384, SHA512 and RIPEMD160. It can be very useful for checking whether downloads are corrupt and for finding identical files.
You can download Hashing from https://github.com/hellzerg/hashing.