MD5
Message Digest 5, a mathematical formula for uniquely representing any amount of data in just 128 bits (16 bytes). MD5, and other hash algorithms (such as SHA-1) are used in cryptography, digital security, computer forensics, and other areas.
Note: If two files have the same MD5 hash value, they are assured (with an astronomical degree of certainty) to have exactly the same contents, bit for bit.