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# How to check md5 hash through Total Commander + MD5 Instruction File Checker

MD5 Message Digest 5 is a 128-bit hash algorithm developed by Professor Ronald L. Rivest of the Massachusetts Institute of Technology (MIT) in 1991. It is intended for creation of "prints" or digests of the message of any length and the subsequent check of their authenticity.

The MD5 algorithm is vulnerable to some attacks, for example, it is possible to create two messages with the same hash sum, so its use is not recommended. Alternatives are the algorithms of the SHA-2 family.

## The scheme of work of algorithm MD5

The input of the algorithm receives an input data stream, the hash of which must be found. The length of the message can be any (including zero). We write down the length of the message in L. This number is an integer and non-negative. Multiplicity of any number is optional. After the data is received, the process of preparing the flow for calculations is in progress.

## Comparison of MD5 and MD4

The MD5 algorithm is derived from MD4. Another round was added to the new algorithm, now there are 4 instead of 3 in MD4. A new constant was added to minimize the effect of the input message, in each round at each step and each time the constant is different, it is summed with the result of F and the data block. The function G = XZ v (Y not (Z)) has been changed instead of (XY v XZ v YZ). The result of each step is added to the result of the previous step, because of this, a faster change in the result occurs. The order of work with input words in rounds 2 and 3 has changed.

## MD5 hashes

The hash contains 128 bits (16 bytes) and is usually represented as a sequence of 32 hexadecimal digits.

Several examples of the hash: `MD5("md5") = 1bc29b36f623ba82aaf6724fd3b16718`

Even a small change in the input message (in our case one bit: ASCII character "5" with code 0x35 16 = 00011010 1 2 is replaced by the symbol "4" with code 0x34 16 = 00011010 0 2 ) results in a complete hash change. This property of the algorithm is called an avalanche effect.

`MD5("md4") = c93d3bf7a7c4afe94b64e30c2ce39f4f`

Example MD5 hash for a "null" string:

`MD5("") = d41d8cd98f00b204e9800998ecf8427e`

## How to check md5 Total Commander

Has dealt with the application of hashing md5 is quite wide, and here we will not breed blah blah on this subject, because we just want to know How to check md5 - checksum and compare it.

If there is no possibility to use the utility, I think the total commander is for everyone.

Select the file for verification, then go File -> Calculate CRC-sums (SFV, MD5 format) ...

A window like this will pop up, tick MD5, ok

Next to the fashim file, one more will be created, with the same name and extension md5.

Select it and open it with the F3 key, we see the checksum. That's how you can check md5 with Total Commander.

## Brief instructions for working with MD5 File Checker

In order to make sure that the downloaded file is identical to the file on the server, you need to compare their checksums. For this purpose, you can use the algorithm for calculating checksums md5.

When you add a cartoon to the server, it calculates this same checksum, you can see it on the information page about the cartoon.

The program does not require installation. For users of Linux, Unix, MacOS and other operating systems, you can see similar programs directly in your OS.

Run the program. On the page with any cartoon in the block of information about the cartoon, we find the field with the checksum md5 and copy it to the clipboard.

• We paste it into the field for check # 2.
• We select the file that we want to check in field # 1.
• We press the button "Check".
• As a result, we receive a message with the result of the program.

For example, "MD5 sum of the file coincides with the checksum - everything is OK.

The file is not corrupt "or" MD5 file sum does not match the checksum. The file may be corrupt. "Draw conclusions.

The additional possibility of the program is the calculation of the checksum md5 for an arbitrary file and its output to the user.