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HMAC algorithm

Saturday, 12 May 2018

HMAC stands for "Keyed-Hash Message Authentication Code." It is a cryptographic algorithm that is used to verify the authenticity and integrity of a message or data.

In HMAC, a secret key is used to create a message authentication code (MAC) for a given message. The MAC is then sent along with the message to the receiver. The receiver can then use the same key to calculate a new MAC for the message and compare it with the received MAC. If the two MACs match, then the message is considered authentic and has not been tampered with.

HMAC can be implemented using various cryptographic hash functions such as SHA-256 or MD5. It is widely used in network protocols such as SSL/TLS, SSH, and IPsec to provide message authentication and integrity. Here's an example of how to use the HMAC algorithm in Python:


import hashlib
import hmac

message = b'This is a message'
secret = b'secretkey'

# create a new HMAC object using the SHA256 hash function
h =, message, hashlib.sha256)

# print the hexadecimal representation of the HMAC digest


in this example, we first import the necessary modules: hashlib for the SHA256 hash function and hmac for the HMAC algorithm. We then create a message and a secret key as bytes objects. We pass these objects to the function along with the SHA256 hash function to create a new HMAC object. Finally, we call the hexdigest() method on the HMAC object to get the hexadecimal representation of the HMAC digest, which we print to the console. hope you enjoy it!

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