So what is this hash thing all about? Well a hash function can be used to map the data in a file to a fixed size. The values returned by a hash function may be called hash values, hash codes, hash sums, or simply hashes. An existing use of hashes that you may of heard of is the hash table, widely used in computer software for rapid data lookup in your computer.

A primary application of hash functions today is for message integrity. The hash value provides a digital fingerprint of a message's contents, which ensures that the message has not been altered by an intruder, virus, or by other means. Hash algorithms are effective because of the extremely low probability that two different messages will yield the same hash value.

Likewise with files particularly during the download process, data loss may occur. However a hash value provides a way of checking if the file's contents have been changed in any way from the original file. Data loss in the file can happen during download from the Internet and the file can be corrupted due to a number of reasons including;

•     Data loss during the download process itself due to instability in the Internet connection or server
•     The file can be tampered due to virus infections
•     Due to Hacker attacks

To ensure that a downloaded file is exactly the same as that of the original file, the use of hashes is a quick way to be certain. MD5 hashes have been widely used in the software world to provide some assurance that a transferred file has arrived intact. For example, file servers often provide a pre-computed MD5 hash, so that a user can compare it to the hash of the downloaded file.

Cite was originally created so that I could check that the Trekker application was uploaded correctly. It can also be used to check that any upload or download is a correct copy of the original software created by the software vendor. Simply go the the software vendors site and cut and paste the hash into Cite. Software vendors can also use Cite to get the hash of their application to supply their users with a hash, and to check that it is has uploaded correctly. Cite currently supports the most popular hashes including MD5, SHA-1 and SHA-2(256bit) hashes. Cite works on Windows XP/Vista/7/8/8.1/10. For more information visit the project page.