HashTab: Add a digital fingerprint to the file attribute

Users who often download software will find that many Download Software websites provide MD5 values (figure 1 ). So what is the MD5 value? The entire process of MD5 is message-digest algorithm 5, short for the information-digest algorithm. It is widely used in encryption and decryption technology. It can be said that it is the "digital fingerprint" of a file ". Any file, no matter what type it is or its size, has a unique MD5 information value.

But why is there an MD5 value after the software? Because a lot of software has been modified, added plug-ins, or added other patches. If this file has been modified, its MD5 value will also change. Therefore, you can check whether the file has been tampered with by comparing the MD5 value of the same file.

Figure 1 MD5 values of different files are different

After downloading the file, you can perform MD5 verification on the downloaded file if you want to know whether the downloaded file is exactly the same as the original file on the website. If the MD5 value is the same as that published on the website, you can confirm that the downloaded file is complete. If the difference exists, it indicates that the file you downloaded has a problem. Either an error occurs during the network download process or the file has been modified by someone else. It is recommended that you do not use the virus to prevent others from modifying the file.

So how can we know whether the MD5 value of the file is modified? Here we will introduce a program named HashTab. After HashTab is installedWindowsThe file Properties window of resource manager adds a tag called "file verification. This label can help you easily calculate the MD5, SHA1 and CRC-32 hash values of the file. These are common hash values when you verify file integrity.

First download HashTab to the hard disk [Official download] and run the downloaded file to start installation. After installation, you can download files from the website. After the file is downloaded, right-click the file and select the file hash value to view the MD5 value, so that you can check whether the file has been modified (figure 2 ). In addition to viewing MD5 values, you can also view SHA1, CRC-32 equivalent.

Figure 2 HashTab: HashTab not only computes the file's MD5, but also compares the file's MD5 value. For example, after installing the system, you can perform MD5 verification on the system files. After a while, if you suspect that some files have been replaced, then, you can perform MD5 verification for the suspected files. First, check the MD5 value of the file, click the "Compare" button, and select the file to be compared, then, the MD5 value is automatically compared to check whether the file is modified. If the MD5 value is the same, the file is normal. If it is different from the previously obtained MD5 verification code, it is certainly a problem. (Figure 3 ).

Figure 3 compare whether the file MD5 is the same

In this way, when downloading an object, you no longer need to worry about the modification of the object. You only need to use HashTab to compare the MD5 value, so that you can easily know whether the MD5 value is the same and determine whether the object is modified.