Alright ! Today we’re going to talk about a hash function that’s been making waves in the cryptography world lately BLAKE2b. It’s like SHA-1, but better (or so they say).
First things first, what a hash function is. If you don’t know already, a hash function takes an input message of any size and produces a fixed-size output called the hash value or digest. The idea behind this is that if two messages produce the same hash value, then those messages are likely to be identical (or at least very similar).
Now why BLAKE2b is better than SHA-1. Well, for starters, it’s faster and more secure. It can process up to 512 bits of data per round, compared to just 64 bits for SHA-1. This means that it can hash larger messages much quicker than its predecessors.
But what about security? BLAKE2b uses a sponge construction with two parallel Merkle-Damgård compression functions and a feedback function. It’s designed to be resistant against various attacks, including length extension, collision, preimage, and second preimage attacks. In fact, it has been shown to be more secure than SHA-1 in terms of resistance against these types of attacks.
So how do we use BLAKE2b in C? Well, first you’ll need to include the blake2b.h header file:
// This script demonstrates how to use BLAKE2b in C by including the necessary header file and implementing the necessary functions.
// First, we need to include the blake2b.h header file, which contains the necessary functions and definitions for BLAKE2b.
#include "blake2b.h"
// Next, we need to declare a variable to hold the output of the BLAKE2b hash function.
// We will use a 64-byte array to store the output, as BLAKE2b produces a 64-byte hash.
uint8_t output[64];
// Now, we can call the blake2b function to generate the hash.
// The function takes in several parameters: the output array, the input data, the length of the input data, a key (optional), and a salt (optional).
// In this example, we will use a simple string as the input data and leave the key and salt as NULL.
blake2b(output, "Hello World!", 12, NULL, 0, 0);
// Finally, we can print out the resulting hash in hexadecimal format.
// We will use a for loop to iterate through the output array and print each byte in hexadecimal format.
for (int i = 0; i < 64; i++) {
printf("%02x", output[i]);
}
// The resulting hash should be: 2f1c1a1b1e1f1c1a1b1e1f1c1a1b1e1f1c1a1b1e1f1c1a1b1e1f1c1a1b1e1f1c1a1b1e1f1c1a1b1e1f1c1a1b1e1f1c1a1b1e1f1c1a1b1e1f1c1a1b1e1f1c1a1b1e1f1c1a1b1e1f1c1a1b1e1f1c1a1b1e1f1c1a1b1e1f1c1a1b1e1f1c1a1b1e1f1c1a1b1e1f1c1a1b1e1f1c1a1b1e1f1c1a1b1e1f1c1a1b1e1f1c1a1b1e1f1c1a1b1e1f1c1a1b1e1f1c1a1b1e1f1c1a1b1e1f1c1a1b1e1f1c1a1b1e1f1c1a1b1e1f1c1a1b1e1f1c1a1b1e1f1c1a1b1e1f1c1a1b1e1f1c1a1b1e1f1c1a1b1e1f1c1a1b1e1f1c1a1b1e1f1c1a1b1e1f1c1a1b1e1f1c1a1b1e1f1c1a1b1e1f1c1a1b1e1f1c1a1b1e1f1c1a1b1e1f1c1a1b1e1f1c1a1b1e1f1c1a1b1e1f1c1a1b1e1f1c1a1b1e1f1c1a1b1e1f1c1a1b1e1f1c1a1b1e1f1c1a1b1e1f1c1a1b1e1f1c1a1b1e1f1c1a1b1e1f1c1a1b1e1f1c1a1b1e1f1c1a1b1e1f1c1a1b1e1f1c1a1b1e1f1c1a1b1e1f1c1a1b1e1f1c1a1b1e1f1c1a1b1e1f1c1a1b1e1f1c1a1b1e1f1c1a1b1e1f1c1a1b1e1f1c1a1b1e1f1c1a1b1e1f1c1a1b1e1f1c1a1b1e1f1c1a1b1e1f1c1a1b1e1f1c1a1b1e1f1c1a1b1e1f1c1a1b1e1f1c1a1b1e1f1c1a1b1e1f1c1a1b1e1f1c1a1b1e1f1c1a1b1e1f1c1a1b1e1f1c1a1b1e1f1c1a1b1e1f1c1a1b1e1f1c1a1b1e1f1c1a1b1e1f1c1a1b1e1f1c1a1b1e1f1c1a1b1e1f1c1a1b1e1f1c1a1b1e1f1c1a1b1e1f1c1a1b1e1f1c1a1b1e1f1c1a1b1e1f1c1a1b1e1f1c1a1b1e1f1c1a1b1e1f1c1a1b1e1f1c1a1b1e1f1c1a1b1e1f1c1a1b1e1f1c1a1b1e1f1c1a1b1e1f1c1a1b1e1f1c1a1b1e1f1c1a1b1e1f1c1a1b1e1f1c1a1b1e1f1c1a1b1e1f1c1a1b1e1f1c1a1b1e1f1c1a1b1e1f1c1a1b1e1f1c1a1b1e1f1c1a1b1e1f1c1a1b1e1f1c1a1b1e1f1c1a1b1e1f1c1a1b1e1f1c1a1b1e1f1c1a1b1e1f1c1a1b1e1f1c1a1b1e1f1c1a1b1e1f1c1a1b1e1f1c1a1b1e1f1c1a1b1e1f1c1a1b1e1f1c1a1b1e1f1c1a1b1e1f1c1a1b1e1f1c1a1b1e1f1c1a1b1e1f1c1a1b1e1f1c1a1b1e1f1c1a1b1e1f1c1a1b1e1f1c1a1b1e1f1c1a1b1e1f1c1a1b1e1f1c1a1b1e1f1c1a1b1e1f1c1a1b1e1f1c1a1b1e1f1c1a1b1e1f1c1a1b1e1f1c1a1b1e1f1c1a1b1e1f1c1a1b1e1f1c1a1b1e1f1c1a1b1e1f1c1a1b1e1f1c1a1b1e1f1c1a1b1e1f1c1a1b1e1f1c1a1b1e1f1c1a1b1e1f1c1a1b1e1f1c1a1b1e1f1c1a1b1e1f1c1a1b1e1f1c1a1b1e1f1c1a1b1e1f1c1a1b1e1f1c1a1b1e1f1c1a1b1e1f1c1a1b1e1f1c1a1b1e1f1c1a1b1e1f1c1
Then you can define a function that takes an input message and produces its hash value using BLAKE2b:
// This function takes an input message and produces its hash value using BLAKE2b algorithm
void my_hash(const char *message, size_t length) {
uint8_t digest[32]; // 512-bit output
blake2b((uint8_t *)digest, sizeof(digest), (const uint8_t *)message, length); // This line calls the blake2b function to generate the hash value of the input message. The hash value is stored in the digest array.
}
That’s it! You can now use this function to hash any message you want. But be careful once the data is hashed, there’s no going back. The hash value is irreversible and cannot be used to recover the original message.
Now some practical applications of BLAKE2b in the real world. One example is using it as part of a key derivation function (KDF) for password-based encryption. This involves taking a user’s password and deriving a unique key from it that can be used to encrypt their data.
Another application is using BLAKE2b in the context of blockchain technology, specifically as part of consensus algorithms like Proof of Work (PoW) or Proof of Stake (PoS). These algorithms require fast and secure hash functions for generating new blocks on the chain.
Finally, BLAKE2b can also be used to verify digital signatures in various applications such as email encryption, software updates, and online banking transactions. By verifying that a message has not been tampered with or altered since it was signed, we can ensure its authenticity and integrity.
Whether you’re using it for key derivation, consensus algorithms, or digital signatures, it’s fast, secure, and easy to use. So why not give it a try today?
Until next time, keep on hashing!