We are all used to sending data over the Internet or other local networks. Typically, that data is transferred over the network in the form of bits. Generally, when tons of data is sent over a network, it is susceptible to loss due to a network problem or even a malicious attack. A checksum is used to ensure that the data received is undamaged and free from errors and losses. The checksum acts as a fingerprint or unique identifier for the data.
To understand it better, consider this: I send you a basket of apples through a delivery man. Now, since the delivery agent is a third party, we cannot completely trust its authenticity. So to make sure you haven't eaten any apples on your way and that you get all the apples, I call you and tell you that I have sent you 20 apples. Upon receiving the basket, you count the number of apples and check if there are 20.
This apple count is what the checksum does to your record. If you have sent a very large file over a network (third party) or have downloaded one from the Internet and want to make sure that the file has been sent or received correctly, you apply a checksum algorithm to your file that is being sent and you communicate the value to the receiver. Upon receiving the file, the receiver will apply the same algorithm and match the value obtained with what you have sent. If the values match, the file was sent successfully and no data was lost. But if the values are different, the receiver will instantly know that some data has been lost or that the file has been tampered with over the network. Since data can be highly sensitive and important to us, it is important to check for any errors that may have occurred during transmission. Therefore, a checksum is very important to maintain the authenticity and integrity of the data. Even a very small change in the data causes a large change in the checksum. Protocols such as TCP / IP that govern Internet communication rules also use checksum to ensure that the correct data is always delivered.
A checksum is basically an algorithm that uses a cryptographic check function. This algorithm is applied on a data or a file before sending it and after receiving it through a network. You may have noticed that it is provided alongside a download link so that when you download the file, you can calculate the checksum on your own computer and match it to the given value. Note that the length of a checksum does not depend on the size of the data but on the algorithm used. The most common checksum algorithms used are MD5 (Message Digest algorithm 5), SHA1 (Secure Hashing algorithm 1), SHA-256, and SHA-512. These algorithms produce hash values of 128, 160, 256, and 512 bits respectively. SHA-256 and SHA-512 are newer and more powerful than SHA-1 and MD5, which in some rare cases produced the same checksum values for two different files. This compromised the validity of those algorithms. The new techniques are error-proof and more reliable. The Hashing algorithm mainly converts the data to its binary equivalent and then carries out some basic operations like AND, OR, XOR, etc. in it and finally extracts the hexadecimal value from the calculations.
What is the checksum? And how to calculate the checksums
Method 1: Calculate checksums using PowerShell
1.Use search in Windows 10 start menu and type PowerShell and click $0027Windows PowerShell$0027 from the list.
2. You can also right-click Start and select "Windows PowerShell" from the menu.
3. In Windows PowerShell, run the following command:
Get-archive your file path For example, Get-FileHash C: N-UsersHpDesktopN-myfile.docx
4.The prompt will show the SHA-256 hash value by default.
5.For other algorithms, you can use:
Get-FileHash yourFilePath -MD5 Algorithm OR Get-FileHash yourFilePath -SHA1 Algorithm
Now you can match the obtained value with the given value.
Method 2: Calculate Checksum Using Online Checksum Calculator
There are many checksum calculators online like $0027onlinemd5.com$0027. This site can be used to calculate MD5, SHA1 and SHA-256 checksums for any file and even for any text.
1.Click the "Choose file" button and open the desired file.
2.Alternatively, drag and drop your file into the appropriate box.
3.Select the desired algorithm and obtain the required checksum.
4.You can also match this obtained checksum with the given checksum by copying the given checksum into the "Compare with:" text box.
5.You will see the check mark or cross next to the corresponding text box.
To calculate the hash of a string or text directly:
a) Scroll down the page to $0027MD5 & SHA1 Hash Generator For Text$0027
b) Copy the string into the given text box to get the required checksum.
For other algorithms, you can use $0027https: //defuse.ca/checksums.htm$0027. This site gives you an extensive list of many different hashing algorithm values. Click "Choose file" to select your file and click "Calculate checksums ..." to get the results.
Method 3: Use the MD5 and SHA Checksum Utility
First, download the MD5 & SHA checksum utility and then launch it by double clicking the exe file. Just browse your file and you can get your MD5, SHA1, SHA-256 or SHA-512 hash. You can also copy-paste the given hash into the corresponding text box to easily compare it with the obtained value.
Hope the above steps have been helpful in learning What is Checksum? and how to calculate it; But if you still have any questions about this article, feel free to ask them in the comment section.