https://github.com/denostack/inthash
Efficient integer hashing library using Knuth's multiplicative method for Javascript and Typescript, perfect for obfuscating sequential numbers.
https://github.com/denostack/inthash
deno hashing obfuscation typescript
Last synced: 12 days ago
JSON representation
Efficient integer hashing library using Knuth's multiplicative method for Javascript and Typescript, perfect for obfuscating sequential numbers.
- Host: GitHub
- URL: https://github.com/denostack/inthash
- Owner: denostack
- Created: 2018-07-09T07:51:55.000Z (almost 7 years ago)
- Default Branch: main
- Last Pushed: 2024-04-13T06:19:07.000Z (about 1 year ago)
- Last Synced: 2025-04-09T08:44:01.295Z (about 1 month ago)
- Topics: deno, hashing, obfuscation, typescript
- Language: TypeScript
- Homepage:
- Size: 2.29 MB
- Stars: 40
- Watchers: 1
- Forks: 0
- Open Issues: 0
-
Metadata Files:
- Readme: README.md
Awesome Lists containing this project
README
# inthash 
inthash is a versatile library for generating integer hash values in Javascript
and Typescript using Knuth's multiplicative method. With a user-friendly
interface, this library allows you to obfuscate predictable numbers, making it
ideal for scenarios like 'Auto Increment' values in databases. inthash supports
`number`, `string`, `bigint`.
## Installation
**Node.js**
```bash
npm install inthash
```
**Deno**
```ts
import { Hasher } from "https://deno.land/x/inthash/mod.ts";
```
## Usage
### Generating Random Settings
Run the following command to generate random settings for your hasher:
```bash
# Node.js:
npx inthash
# Deno:
deno run jsr:@denostack/inthash/cli
# Bun
bunx inthash
# Output:
# {
# "bits": 53,
# "prime": "6456111708547433",
# "inverse": "3688000043513561",
# "xor": "969402349590075"
# }
```
### Creating and Using a Hasher
Create a hasher with the generated settings:
```ts
const hasher = new Hasher({
bits: 53, // Javascript, Number.MAX_SAFE_INTEGER
prime: "6456111708547433", // Random Prime
inverse: "3688000043513561", // Modular Inverse
xor: "969402349590075", // Random n-bit xor mask
});
const encoded = hasher.encode(100); // result: 6432533451586367
const decoded = hasher.decode(encoded); // result: 100
```
```ts
// You can obfuscate predictable numbers like 'Auto Increment'!
hasher.encode(0); // 969402349590075
hasher.encode(1); // 6085136369434450
hasher.encode(2); // 4132187376469225
hasher.encode(3); // 2180123214014976
hasher.encode(Number.MAX_SAFE_INTEGER - 3); // 2024647471942759
hasher.encode(Number.MAX_SAFE_INTEGER - 2); // 6827076040726014
hasher.encode(Number.MAX_SAFE_INTEGER - 1); // 4875011878271765
hasher.encode(Number.MAX_SAFE_INTEGER); // 2922062885306540
```
inthash also supports `string` and `bigint` values:
```ts
// String input and output
const encoded = hasher.encode("100"); // "6432533451586367"
const decoded = hasher.decode(encoded); // "100"
```
```ts
// BigInt input and output
const encoded = hasher.encode(100n); // 6432533451586367n
const decoded = hasher.decode(encoded); // 100n
```
### Handling MySQL `bigint(20)`
To work with `bigint(20)` in MySQL, you need to handle 64-bit values. The old
version of IntHash supported up to 53-bit values
(`Number.MAX_SAFE_INTEGER === 2**53 - 1`). From v3 onwards, n-bit values are
supported:
```bash
# Node.js:
npx inthash -b64
# Deno:
deno run https://deno.land/x/inthash/cli.ts -b64
# Output:
# {
# "bits": 64,
# "prime": "16131139598801670337",
# "inverse": "14287487925114175297",
# "xor": "8502035541264656686"
# }
```
## See also
- [optimus](https://github.com/jenssegers/optimus) A PHP implementation of
Knuth's multiplicative hashing method. inthash is inspired by and ported from
this library.