This online free MD5 hash generator tool allows you to generate the MD5 hash of any string. It is very useful in encoding passwords, credit card information, and other sensitive data into MySQL or other databases. It provides a super quick and easy way to encode an MD5 hash from a simple string.

MD5 stands for Message Digest algorithm 5 and is one in a series of message digest algorithms designed by US cryptographer Professor Ronald Rivest in 1991 to replace an earlier hash function MD4.

The professor Ronald Rivest developed the first hash function MD2 in 1989, which was built for 8-bit computers. Although MD2 is still in use, it is not recommended for applications that need a high level of security, because it is vulnerable to various attacks.

MD2 was then replaced by MD4. MD4 was made for 32-bit machines and was faster than MD2. MD5 was released in 1991 and was also built for 32-bit machines. MD5 is not as fast as MD4, but it is considered to be more secure than the previous ones.

MD5 checksums are built to be non-reversible which means that you cannot look at the checksum and identify the original inputted data. Hash functions are also called one-way functions because they must not be reversible. For example, if an attacker can easily reverse a hash function, the concept of the function will be totally useless.

When the MD5 hash generator finishes processing your request, you can already send the MD5 hash to your recipient. You can check the integrity of your MD5 hash. If it gives you the same results, it means that the string is verified.

The basic idea behind cryptographic hashing is to take an arbitrary block of data and return a fixed “hash” value. It can be any data, of any size but the hash value will always be fixed.

The MD5 hash is created by taking a string of any length and encoding it into a 128-bit fingerprint. Encoding the same string using the MD5 algorithm will result in the same 128-bit hash output. The MD5 message-digest hashing algorithm processes the data in 512-bit blocks, then divides it into 16 words composed of 32 bits each. The output is a 128-bit message-digest value. If we input www.w3docs.com into an MD5 hash value then the result will be the following: 550850e0a6ddfa733aea39dff93c13ad.

There are some stages that the computation of the MD5 is performed. The first stage begins with the message-digest values initialized using hexadecimal numerical values. Each stage includes four message-digest passes that manipulate values in the current data block and values processed from the previous block. The final stage is the computed value from the last block becomes the MD5 digest for that block.

MD5 hashes are also used to ensure the data integrity of files. The users can compare a hash of the source file with a newly created hash of the destination file to check that it is intact and unmodified because the algorithm always produces the same output for the same given input. Hashes are designed to produce a string of characters. Regardless of the size of the inputted data, the strings have a fixed length. The number of inputs has no limit, but the outputs are limited to a specific number.

While there are several different classes of cryptographic hash functions, they all share the same four properties. Here are the 4 qualities a cryptographic hash function must have to be useful.

Here are several qualities that hush functions must have to be useful and secure.

- The hash functions must be computationally efficient. It is very important because if the computer processes a cryptographic hash function and receive the output in a very long period of time it will not be very practical. To be useful, hash functions must be computationally efficient.
- The most important idea about the hash function is that the output must not reveal any information about the input. This is called pre-image resistance. The cryptographic hashing algorithms can receive any kind of input. The input can include numbers, letters, words, or punctuation marks, a single character, a sentence from a book, a page from a book, or an entire book. The fixed output guarantees the security because if a longer input produced a longer output, then attackers would already have a seriously helpful clue when trying to discover someone’s private input. In addition, changing one character in a long string of text must result in a radically different digest. If a cryptographic hash function produced different outputs each time for the same input was entered, it would be against the whole point of hash functions.
- The hash function must have collision resistance meaning that it must be impossible to find two different inputs that produce the same output.
- Cryptographic hash functions must be deterministic. In other words, for any given input, a hash function must always give the same result. If you put in the same input a hash function must produce the same exact output. As mentioned above, the inputs to a hash function can be of any length. This means there are infinite possible inputs that can be entered into a hash function. Hash functions are part of information security methods. A hash function is simply a function that takes in input value and creates an output value deterministic of the input value. For any x input value, you will always receive the same y output value whenever the hash function is run. The best way to demonstrate hash function is with a modular function which is also called modular arithmetic or clock arithmetic. Modular functions are mathematical functions that, put simply, produce the remainder of a division problem.

MD5 is not an encryption algorithm. A lot of people are under the impression that MD5 encrypts data. All it does is compute a hash value for a given set of data.

## MD5 Security

The basic goal of any message-digest function is to produce random output. To be considered cryptographically secure, the hash function should meet two requirements:

- it is impossible for an attacker to generate a message matching specific hash value.
- it is impossible for an attacker to create two messages that produce the same hash value.

Though formerly designed as a cryptographic message authentication code algorithm, MD5 hashing is no longer considered reliable for use as a cryptographic checksum because researchers have demonstrated techniques capable of easily generating MD5 collisions.

But if you intend to use MD5 as a simple checksum algorithm or for a unique constraint on a database table, it will work perfectly. You can use the SHA-256 generator tool instead of MD5.