MD5 hash calculator

# What is MD5?

The MD5 (Message-Digest Algorithm) is cryptographic hash function that calculates a 128-bit hash value. MD5 is used in to check data integrity in security applications. In other words MD5 checksum is like a fingerprint of the file. There is almost no possibility that two identical MD5 hash values are calculated of two different files. That is way MD5 hashes have a lot of use cases, some of which are: detecting data changes, storing or generating strong passwords, making unique keys in databases and ensuring message integrity.

MD5 is a cryptographic hash function used as an encryption of fingerprint function for a file. Instead of confirming that two sets of data is identical by comparing the raw data we can use checksum.

In the other words you can use MD5 checksum to verify integrity of your downloaded file. For this you need to confirm that the checksum you are getting at your PC or MAC is the same as one on the website. Once you confirm that it is the same you know for sure your file was not changed.

The file could be altered by the following reasons:

• Data loss during the download, due to instability in the network.
• The file could be changed by malware or virus.
• It could have code snippets inserted by the hackers.

# How long is MD5 hash?

MD5 hash is always fixed size it is 128bit string or 32 hex digits long.

The idea behind the algorithm is what you can convert any size or length data (text or binary) to fixed size “hash value” output.

# What is the difference between MD4 and MD5?

• MD5 algorithm has four rounds (64 steps), where MD4 algorithm (48 steps) has only three.
• Each step of MD5 has unique additive constant, T(i), where each round of MD4 uses fixed constant.
• The function G in the second round of MD5 is less symmetric than the G function in MD4.

The MD5 algorithm is designed to be quite fast on 32-bit machines. In addition, the MD5 algorithm does not require any large substitution tables; the algorithm can be coded quite compactly.

# What is cryptographic hash function?

Cryptographic hash function is a hash function which takes a data (input) and calculates a fixed-size string of bytes. This string is called hash value or checksum.

Three ideal hash functions properties are as follows:

• Easy to calculate for any data provided.
• Very difficult to find alphanumeric text that has a given hash.
• It is extremely unlikely two find the same hash for different data (input).

With this MD5 hash calculator you can easily calculate MD5 hashes online.