A MAC (Message Authentication Code) or HMAC (Hash-based Message Authentication Code) is a cryptographic mechanism that can be used to verify the authenticity of a message. Both these terms are often used interchangeably, but they are different from each other and serve different purposes. A hash function is an algorithm that takes a variable length input and returns a fixed length output with no way to reverse engineer the input from the output. It works by taking an input and assigning it to an output based on its properties in order to create a fingerprint for this input. A hash function is a good way of storing data so that you can check if it has been changed without needing to store the original data again. It’s also useful as a check on data when you have to re-check it later, but don’t want to store it again—for example, in error-checking systems or password verification systems.
MAC
MAC stands for Message Authentication Code. This is a system for generating an encrypted code for a message that can be decrypted by the receiver. In order to authenticate the sender and message, the receiver uses a secret key in order to decrypt the message and check the code. A MAC is generally used for encrypted communication, for example when you log into a website over an unsecured network where it’s possible for someone to listen in on your communication. In this scenario, the website will use a MAC to verify that you are who you say you are, and that the communication is coming from you. A MAC is much like a digital signature, but they are not the same thing. A digital signature is used to verify the authenticity of a message and the identity of the sender. A MAC, on the other hand, is used to verify that the message has not been altered in any way.
HMAC
HMAC stands for Hash-based Message Authentication Code. A message authentication code is a cryptographic mechanism that can be used to verify the authenticity of a message. In order for a receiver to authenticate a message, he/she must have a secret key. A key is a variable-length input that is combined with the message to create a fixed-length output. The key is used to decrypt the message and check the code. A hash function is an algorithm that takes a variable length input and returns a fixed length output with no way to reverse engineer the input from the output. It works by taking an input and assigning it to an output based on its properties in order to create a fingerprint for this input.
Read Related Also: Has Putin lost his milblogger propagandists — and Kherson?
Difference between MAC and HMAC
– A MAC is used to verify the authenticity of a message and the identity of the sender while an HMAC is used to verify that the message has not been altered in any way. – A MAC requires a shared secret key between the sender and the receiver, while an HMAC requires that the secret key is shared between the sender and the receiver, as well as the hash function. – A MAC, similar to a digital signature, is based on a single cryptographic hash with a unique identifier, while an HMAC uses a combination of two or more independent hash functions to create a unique code, making the system more secure. – An HMAC usually has a longer key length than a MAC, making it harder to break. – The length of an HMAC code can vary depending on the hash function used and is not fixed as it is with a MAC. – HMAC is generally easier to implement than a MAC, making it the preferred method of authentication.
Summary
A MAC is a method that uses a secret key to generate a code that can be decrypted by the receiver in order to verify the authenticity of a message. An HMAC is a method that uses a secret key to generate a code that can be decrypted by the receiver in order to verify that the message has not been altered in any way. The main difference between MAC and HMAC is the function, as well as the secret key used to create the code, and the way in which the code is created.
