What are the Similarities & differences between the Checksum Algorithm and the Hash Function? can they be used in place of one another or is
Is their usage different from each other?
I reviewed many articles on web and came across an article that says -
A checksum is intended to verify (check) the integrity of data and identify data-transmission errors, while a hash is designed to create a unique digital fingerprint of the data. A checksum protects against accidental changes. A cryptographic hash protects against a very motivated attacker.
To properly understand the differences & similarities between Checksum vs Hash, we need to understand both simultaneously.
A checksum is used to determine if something is the same. If you have downloaded a file, you can never be sure if it got corrupted on the way to your machine. You can use cksum to calculate a checksum (based on CRC-32) of the copy you now have and can then compare it to the checksum the file should have. This is how you check for file integrity.
A hash function is used to map data to other data of fixed size. A perfect hash function is injective, so there are no collisions. Every input has one fixed output. A cryptographic hash function is used for verification. With a cryptographic hash function you should not be able to compute the original input. A very common use case is password hashing. This allows the verification of a password without having to save the password itself. A service provider only saves a hash of a password and is not able to compute the original password. If the database of password hashes gets compromised, an attacker should not be able to compute these passwords as well. This is not the case, because there are strong and weak algorithms for password hashing. You can find more on that on this very site.
TL;DR:Checksums are used to compare two pieces of information to check if two parties have exactly the same thing. Hashes are used (in cryptography) to verify something, but this time, deliberately only one party has access to the data that has to be verified, while the other party only has access to the hash.
I am an expert in the field of checksums, hash functions, and data integrity. My depth of knowledge is evident in various areas, including cryptographic hash functions, checksum algorithms, and their practical applications. I'll demonstrate my expertise by addressing the question about the similarities and differences between the Checksum Algorithm and the Hash Function, and how they can be used interchangeably or if their usage differs.
Checksum Algorithm vs. Hash Function:
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Purpose:
- Checksum Algorithm: It is designed to verify the integrity of data and identify data-transmission errors. Checksums are particularly useful for detecting accidental changes in data during transmission.
- Hash Function: Its primary purpose is to create a unique digital fingerprint or hash value for data. Hash functions are commonly used in cryptography for data verification and ensuring data integrity against intentional tampering.
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Functionality:
- Checksum Algorithm: Utilized to compare two pieces of information to check if they are identical. For example, it is commonly used to verify file integrity by calculating a checksum based on CRC-32.
- Hash Function: Maps data to a fixed-size output, creating a unique hash value. A cryptographic hash function ensures that it is computationally infeasible to derive the original input from the hash.
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Use Cases:
- Checksum Algorithm: Mainly employed for data integrity checks, such as ensuring that downloaded files are not corrupted during transfer.
- Hash Function: Widely used in cryptography, particularly for password hashing. It allows verifying passwords without storing the actual password; only the hash is stored.
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Security:
- Checksum Algorithm: Provides protection against accidental changes and errors but is not designed for strong security against intentional attacks.
- Hash Function: Cryptographic hash functions offer a higher level of security, protecting against intentional tampering and providing a unique identifier for data.
In summary, while both checksums and hash functions involve creating a digital representation of data, their purposes and use cases differ significantly. Checksums are more focused on data integrity, detecting accidental errors, while hash functions, especially cryptographic ones, are designed for secure data verification, protecting against intentional tampering. They serve distinct purposes and are not interchangeable in most scenarios.
FAQs
The cryptographic hash function takes an input and produces a fixed-length sequence of numbers and letters. The checksum is of the same length, regardless of the original file's size. When a user creates a file and makes copies of it, the file always has the same hash code.
What is the difference between hashing and hash? ›
Hashing is the process of mapping any arbitrary size data into a fixed-length value using a hash function. This fixed-length value is known as a hash value, hash code, digest, checksum, or simply hash.
What is the difference between checksum and digest? ›
Digests are like checksums, but provide such a good ngerprint of the data that it is actually computationally infeasible to change the data without also changing the data's digest. This special property provides new guarantees of integrity that lead to some surprising applications.
What is the primary difference between a hash and hashed message authentication code? ›
The main difference is conceptual: while hashes are used to guarantee the integrity of data, a MAC guarantees integrity AND authentication.
What is checksum with example? ›
Checksum is the redundant bits that are attached with actual data. Sometimes, a Checksum is also considered as a hash sum or hash value. On the sender's side, this method uses a checksum generator to generate a Checksum. On the receiving end, a checksum checker is used to validate whether the correct data is received.
What is the difference between sum and checksum? ›
sum calculates and displays a checksum for each input file. A checksum is an error-checking technique used by many programs as a quick way to compare files that have been moved from one location to another to ensure that no data has been lost. It also displays the number of 512-byte blocks in each file.
What is hashing and example? ›
Hashing is the process of transforming any given key or a string of characters into another value. This is usually represented by a shorter, fixed-length value or key that represents and makes it easier to find or employ the original string.
What is the difference between hashing and Hashcode? ›
Hashing means using some function or algorithm to map object data to some representative integer value. This so-called hash code (or simply hash) can then be used as a way to narrow down our search when looking for the item in the map.
What is the difference between hash key and hash value? ›
The hashing key is the raw data in which to be hashed. The hashing algorithm is the algorithm which performs a function to convert the hash key to the hash value. the hash value is what is produced as a result of the hash key being passed into the hashing algorithm.
What is the difference between hash and checksum in Python? ›
You can use cksum to calculate a checksum (based on CRC-32) of the copy you now have and can then compare it to the checksum the file should have. This is how you check for file integrity. A hash function is used to map data to other data of fixed size. A perfect hash function is injective, so there are no collisions.
If the checksum value the user calculates is even slightly different from the checksum value of the original file, it can alert all parties in the transmission that the file was corrupted or tampered with by a third party, such as in the case of malware.
What are the benefits of checksum? ›
Checksum benefits
Checksums are a simple and effective way to ensure the integrity of digital data. By providing an added layer of protection against data corruption, checksums can help to improve the security and reliability of digital systems. However, they do not provide any error correction.
What is the basic difference between hashing and encryption is that hashing? ›
Hashing vs Encryption – Hashing refers to permanent data conversion into message digest while encryption works in two ways, which can encode and decode the data. Hashing helps protect the integrity of the information and Encryption is used to secure the data from the reach of third parties.
What is the difference between a MAC and a hash? ›
A message authentication code (MAC) is similar to a cryptographic hash, except that it is based on a secret key. When secret key information is included with the data that is processed by a cryptographic hash function, the resulting hash is known as an HMAC.
What is the primary difference between a hash and HMAC? ›
They are message encryption, message authentication code, and hash functions. The major difference between MAC and hash (HMAC here) is the dependence of a key. In HMAC we have to apply the hash function along with a key on the plain text. The hash function will be applied to the plain text message.
What is sha256 hash or checksum? ›
An SHA-256 checksum is a sequence of numbers and letters that you can use to check that your copy of a downloaded update file is identical to the original. Small changes in a file produce very different looking checksums. A single character difference produces a very different looking checksum.
What is the difference between checksum and Hashbytes in SQL Server? ›
CHECKSUM computes a 32-bit integer value by quite simple-minded XOR-algorithm. hashbytes uses a more sophisticated algorithm, and the value is longer. If you want a unique hash value to use for comparison rather than comparing the base values, you cannot use checksum, because the risk for collisions is too big..
What is the difference between checksum and MD5? ›
cksum does a 32 bit ckecksum (CRC-32), while md5sum does a "more reliable" 128 bit checksum. cksum being simpler, it may be faster in some cases, but it may also not be the case because md5sum has been highly optimized for speed. cksum is part of POSIX, and may be present on some systems where md5sum is not.
What is the purpose of the checksum? ›
A checksum is a small-sized block of data derived from another block of digital data for the purpose of detecting errors that may have been introduced during its transmission or storage. By themselves, checksums are often used to verify data integrity but are not relied upon to verify data authenticity.
