Understanding Hashes in JavaScript
In modern web development, ensuring data authenticity and integrity is critical. While many developers rely on standard libraries, understanding the mechanics of a custom JS hash function allows for specialized applications like digital signatures and secure message authentication.
This guide explores a unique approach to mathematical hashing in JavaScript, utilizing recurrence series and large-scale integer manipulation.
What is a One-Way Hash? | Explanation for JavaScript Kids
A one-way hash is a cryptographic function that transforms an input into a unique string of characters. It is designed to be non-revertible encryption; you can easily generate a hash from a message, but it is computationally impossible to reconstruct the original message from the hash. This makes it ideal for verifying data without exposing the raw information.
The Mathematical Foundation for the JavaScript Hash Algorithm
The core of this algorithm is based on a specific mathematical recurrence series. By applying a formula to the character codes of a string, we create a high-entropy output.
The Recurrence Equation | Maths Explanation for JavaScript Kids
The algorithm utilizes the following series to generate the hash weight:
Where:
- $n$ represents the position of the character.
- $t_1$ is the initial seed or value derived from the character code.
Implementing the Custom Hash in JavaScript
To ensure precision during complex calculations, we utilize a JavaScript BigInt approach. This prevents rounding errors often found in standard floating-point arithmetic when dealing with large numbers.
Key Features of the JavaScript Hash Implementation:
- Character Code Processing: Using `charCodeAt`, the algorithm iterates through each string element to gather raw data.
- Bitwise Rotation: To increase security, the output undergoes a bitwise rotation based on the modulo of the recurrence result, ensuring that small changes in input (avalanche effect) result in vastly different hashes.
- Digital Signatures: The resulting hash can be used as a signature to verify that a file or message has not been altered.
Create 2 new files; On Notepad++: File, New.
Call them Hashes.html
and Hashes.js
respectively.
Type out the adjoining JavaScript Hashing Algorithm.
Why Use Custom Mathematical Hashing? | Explanation for JavaScript Kids
Implementing tertiary level JavaScript math in your security protocols offers several benefits:
- No Dependencies: Perform secure checks without bloating your project with external libraries.
- Educational Insight: Gain a deeper understanding of how cryptographic authenticity is calculated at a low level.
- Performance: Tailored algorithms can be optimized for specific data types, providing faster verification for niche applications.
Hashing vs Encryption | Explanation for JavaScript Kids
Although hashing and encryption are sometimes confused, they serve different purposes.
- Encryption is reversible. Encrypted data can be decrypted using a key.
- Hashing is non-reversible. Once data is hashed, it cannot be restored to its original form.
This distinction makes hashing particularly suitable for sensitive data such as passwords, where systems only need to verify correctness rather than retrieve the original value.
Properties of a Good Hash Algorithm | Explanation for JavaScript Kids
- Deterministic: The same input always produces the same output.
- Collision Resistant: Different inputs should not produce the same hash.
- Non-Reversible: Hashes cannot be converted back to the original input.
- Efficient: Quick to compute even for large inputs.
Applications of Hashing in JavaScript
JavaScript hashing is commonly used in a variety of real-world scenarios:
- Password verification: Systems store hashed passwords instead of plaintext values
- Data integrity checks: Hashes ensure data has not been altered
- Authentication mechanisms: Hashes help verify user credentials securely
- Digital signatures: Hash values confirm message authenticity
In each case, hashing allows systems to confirm data validity without exposing sensitive information.
Hash Collisions and Their Implications
A hash collision occurs when two different inputs produce the same hash output. While collisions are theoretically unavoidable, good hash algorithms make them extremely rare.
In practice, collision resistance is essential for maintaining trust in systems that rely on hashes for security and verification.
Summary: JavaScript Hashing Algorithm
Hashes in JavaScript provide a secure and efficient way to represent data using one-way hash functions. By producing fixed-length, non-reversible outputs, hash algorithms play a critical role in data security, authentication, and integrity verification.
Understanding how JavaScript hash functions work - and when to use them - is essential for building reliable and secure web applications.
JavaScript Code for Hashes - .html
<html lang="en">
<head>
<meta charset="utf-8" />
<meta name="viewport" content="width=device-width, initial-scale=1.0">
<title>Hashes</title>
<script src="Hashes.js"></script>
</head>
<body>
<h3>One Way Encryption</h3>
<!-- This is where the result will be displayed when it is ready.-->
<div id="word_hash"></div>
<script>
const message = "merry xmas";
const result = hashWord(message);
document.getElementById("word_hash").innerHTML +=
"Message is '" + message + "';<br/><br/>Encrypted version is '" + result + "'.";
</script>
</body>
</html>
JavaScript Code for Hashes - .js
function hashWord(msg_str) {
// encoding eqn { Tn = (n-2)t1 + 2^n } - please use your own eqn
let hash = 0;
let n;
let t1;
let x;
for (let i = 0; i < msg_str.length; i++) {
// get unicode of this character as n
n = BigInt(msg_str.charCodeAt(i));
t1 = BigInt(i + 1);
// use recurrence series equation to hash
x = (n - 2n) * t1 + 2n ** n;
if (i === 0) {
hash = x;
continue;
}
// bitwise rotate left with the modulo of x
const binary = hash.toString(2);
x = (x % BigInt(binary.length)).toString();
let slice_1 = binary.slice(x).split('');
// keep as '1' to preserve hash size
slice_1[0] = 1;
const slice_2 = binary.slice(0, x);
hash = "0b" + String(slice_1.join('')) + String(slice_2);
hash = BigInt(hash);
}
hash = hash.toString(16);
hash = hash.toUpperCase();
return hash;
}