MD5 is a cryptographic mix function algorithm also known as “message-digest”. This contains a series of digits generated by a one-way hashing procedure. Message digests are specially designed to safeguard the integrity of a piece of information or media and to identify if there are changes and alterations to any part of a message. Message digests are protected one-way hash functions that take random-sized data and produce a fixed-length hash value.
The main function of MD5 is to calculate a hash value in cryptography. While the hash function is to get blocks of data and return them with a fixed-size bit string or hash value. The data that has been utilized by hash functions is referred to as a "message"; while, the calculated hash value is "message digest". The MD5, together with the other hash functions, is commonly used in creating digital signatures and message verification codes, indexing data in hash tables, detecting copied data, for finger-printing, to sort and identify files, and act as checksums in detecting unintentional data corruption.
MD5 hash is used to ensure the data integrity of files because the MD5 hash algorithm has a unique way of producing the same results for the same set of data. MD5 users are allowed to compare a hash of the data source with the newly generated hash on the destination of the file; this helps the user to check if the hash is intact and unaltered. Knowing that MD5 hash is NOT an encryption but only a fingerprint of the given input. Then, you must also understand that it is a one-way process, which means the user is not allowed to reverse a generated MD5 hash to recover the original string.
MD5 can produce a 128-bit (16 bytes) hash value, and it is characterized by a hexadecimal number of 32 digits.