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Example of MD5 hashing in Java

MD5 is a hashing agglorhythm that allows you to generate a key to indecrypt a specific block of data. A typical example of using the MD5 algorithm: to search for duplicates of any files on the hard disk, an MD5 of each file is created and the resulting values are compared. This allows you to significantly speed up the search process, since you do not need to compare the contents of each file.

Also, the MD5 hashing algorithm is often used to verify the data, integrity and completeness of information downloaded from the Internet. For example, on torrents, some files are provided with a hash value.

PREVIOUSLY, MD5 was used to hash passwords, but it soon turned out to be vulnerable. The most common problem was the ability to generate the same hash amounts for 2 messages, so now MD5 is not used in large projects.

Creating a Java Project

First, let's create a project (for convenience, I use the Maven project) and connect the library in the dependencies of our project:


Own implementation of MD5 algorithm in Java



Apache Common Codec MD5 Use Case Study


As you can see, the DigestUtils utility class has a method md5Hex(String st), which contains the MD5 implementation


As you can see, Apache Common Codec is very easy to use and frees us from routine work, where it is easy to make a mistake.