MD4 Hash Generator

MD4 Hash Generator

This free MD4 hash generator online tool generates the MD4 hash of a given input and returns a fixed-size string of characters, which is typically a 'digest' that is unique to the unique input that was used to generate it. It is generally used to verify the integrity of a file or to store a password in a secure way.

Created by Commontools | Updated on: January 27, 2023



What is MD4?

The "Message Digest 4" (also abbreviated as "MD4") algorithm is a cryptographic hash function that Ronald Rivest developed in the year 1990. Its digest length of 128 bits has allowed it to be the basis for subsequent designs such as MD5, SHA-1, and RIPEMD. A non-linear function is used throughout the algorithm's execution, which involves carrying out a total of 48 operations over the course of three rounds of 16.

The security of MD4, on the other hand, has been severely undermined as a result of the publication since 1995 of a variety of full collision and preimage attacks. In spite of this, a modification of MD4 is still used in the ed2k URI scheme for the purpose of identifying files on P2P networks such as eDonkey2000 and eMule.

In addition to that, it was implemented in earlier versions of the Rsync protocol than version 3.0.0.

Now, let's take a look at how the MD4 algorithm works broken down into its simplest form.

MD4 Algorithm

The MD4 algorithm, which is described in RFC 1320, will take as its input a message that is up to 264 bits in length, and it will produce a hash that is 128 bits in length as its output. Both of these numbers are relative to the length of the original message. The MD4 algorithm, as described in RFC 1320, accepts as input a message that may be up to 264 bits in length and generates a hash that is 128 bits in length as output.

  • First, the message is padded to make sure that the total number of bits it contains is equal to 448 mod 512. To do this, a bit value of 1 is added to the end of the message, followed by as many bit values of 0 as are needed to meet the padding condition.
  • After that, a 64-bit representation of the message's initial length is added at the very end of the padded message. This representation is in little-endian format.
  • The message is then broken up or divided into 16-word blocks, and each block is put through a compression function individually.
  • This process is repeated to generate the final output hash.

Now that we have that out of the way, let's look at how you can use our tool to generate the MD4 hash of any plain or cipher text for free.

What is the MD4 hash generator tool?

An MD4 Hash Generator Online Tool gives users the ability to generate the MD4 hash of any message or piece of data. In most cases, the user enters the message into a text field, and the tool will then generate the MD4 hash of the input data.

The user is given the option of selecting the input type, which can either be hexadecimal or plain text. The generated hash value is typically presented in a text field as the output, and it is frequently possible to copy and paste the value into the clipboard for subsequent use.

How to Generate an MD4 Hash Online?

  1. You will find a text input field in the section labeled "Input"; this is where you will type in the message or data that you want to hash.
  2. You will also find an option to select the type of input, which can be either hexadecimal or plain text. Make your selection using the correct option.
  3. Click the "Hash" button once you have completed entering the message and selecting the appropriate input type.
  4. After that, the tool will generate an MD4 hash of the data that was entered and show it in the section labeled "output".
  5. The output will be a string of characters with a fixed-size length, which is known as a "digest," and it will be distinct from the input data in its entirety.
  6. You can copy the generated hash by clicking on the "Copy" button or by selecting the hash and using the keyboard shortcut "Ctrl + C" (or "Cmd + C" on Mac).


Let's look at some examples of what our MD4 hashing tool can do with input and output:

Example 1:

Input: "Hello, world!" (plain text)

Output: "94e3cb0fa9aa7a5ee3db74b79e915989" (hexadecimal)

Example 2:

Input: "Free Online MD4 Hash Generator" (plain text)

Output: "cce71ef4d24c06b3bf8db12852619b6d" (hexadecimal)


MD4 was once widely used in a variety of applications; however, due to well-documented flaws, it is no longer considered a secure hashing algorithm and should not be used for cryptographic purposes. The following is a list of some of the applications in which MD4 has been used in the past:

  • Digital signature: MD4 was used as a hash function in digital signature schemes, such as RSA's MD4-based scheme. One example of this is a digital signature that was generated using MD4.
  • File integrity verification: Verification of a file's integrity MD4 was used to generate a one-of-a-kind hash of a file, which could then be used at a later time to verify the file's integrity.
  • P2P file sharing: The ed2k URI scheme used MD4 to provide a unique identifier for a file within the eDonkey2000 and eMule P2P networks.
  • Data synchronization: Before version 3.0.0, the rsync protocol relied on MD4 to determine which files on multiple systems were identical.
  • Password storage: Hashing passwords with MD4 was common practice for a while, but this method is no longer considered safe due to the fact that it can result in collisions. Password storage.

Again, it is essential to emphasize the significance of the fact that MD4 is no longer regarded as secure and must never be utilized for any cryptographic purpose. Instead, more recent hash functions, such as SHA-256 and SHA-512, which are both more secure, should be used.

MD4 Collision Example

When two different inputs result in the same output hash, this is known as a collision in the context of cryptographic hash functions. Two distinct messages, m1 and m2, that produce the same 128-bit hash value when hashed with the MD4 algorithm are an illustration of a collision in the algorithm.

Let's understand this with an example:

m1 = 839c7a4d7a92cb5678a5d5b9eea5a7573c8a74deb366c3dc20a083b69f5d2a3bb3719dc69891e9f95e809fd7e8b23ba6318edd45e51fe39708bf9427e9c3e8b9
m2 = 839c7a4d7a92cbd678a5d529eea5a7573c8a74deb366c3dc20a083b69f5d2a3bb3719dc69891e9f95e809fd7e8b23ba6318edc45e51fe39708bf9427e9c3e8b9

As we can see above,

m1 ≠ m2, but MD4(m1) = MD4(m2) = 4d7e6a1defa93d2dde05b45d864c429b

MD4 has a well-known flaw, which makes it relatively simple to find collisions; it is strongly discouraged from being used in any cryptographic applications.

Drawbacks of MD4

MD4 has a number of flaws and drawbacks that are well known, and as a result, its use in cryptographic applications is no longer considered to be safe. The following are some of MD4's most significant drawbacks:

  1. Collision vulnerability: MD4 is susceptible to collision attacks, which means that an adversary can find two distinct messages that both result in the same MD4 hash. Because of this vulnerability, MD4 is often used in conjunction with other hashing algorithms. This can potentially be used to tamper with files or forge digital signatures.
  2. Preimage vulnerability: MD4 is also vulnerable to preimage attacks, which means that an adversary can find a message that corresponds to a given MD4 hash value. This means that MD4 should not be used when sensitive information is transmitted. This has the potential to be used to crack password hashes or to manipulate files in some way.
  3. Weak security: The security of MD4 has been severely breached, and the hashing algorithm can no longer be trusted to provide privacy protection. As of the year 2007, an attack can generate collisions in fewer than two operations of the MD4 hash function.
  4. Not recommended by NIST: Since MD4 is not regarded as a secure cryptographic Hash function, the National Institute of Standards and Technology (NIST) does not recommend using it (National Institute of Standards and Technology).

As a result of these deficiencies, the MD4 cryptographic hash function is no longer regarded as a secure cryptographic hash function and should not be utilized for any cryptographic purpose. Instead, more recent hash functions, such as SHA-256 and SHA-512, which are both more secure, should be used.


This page presents the MD4 Hash Generator Online Tool, which gives users the ability to generate the MD4 hash of any message or piece of data. In addition to that, we went over the definition of MD4, its algorithm, the operation of our tool, some examples, some applications, drawbacks and one collision example.


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MLA Style Citation

"MD4 Hash Generator.", 2023. Mon. 06 Feb. 2023. <>.

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