siphash

siphash.js
==========

A pure Javascript implementation of
SipHash

> SipHash is a family of pseudorandom functions optimized for short
> inputs. Target applications include network traffic authentication and
> hash-table lookups protected against hash-flooding denial-of-service
> attacks. SipHash has well-defined security goals and competitive
> performance.

This package also includes implementations of SipHash-1-3, SipHash128, and SipHash128-1-3.

Installation
------------

Server-side installation (io.js/nodejs):

$ npm install siphash

Browser-side/single-line minified version: use
lib/siphash.js.min.

Usage
-----

``javascript
var siphash = require("siphash"),
key = siphash.string16_to_key("This is the key!"),
message = "Short test message",
hash_hex = siphash.hash_hex(key, message);
`

A key is an array of 4 integers, and each of them will be clamped to
32 bits in order to build a 128-bit key.
For a random key, just generate 4 random integers instead of calling
string16_to_key().

`javascript
var siphash = require("siphash"),
key = [ 0xdeadbeef, 0xcafebabe, 0x8badf00d, 0x1badb002 ],
message = "Short test message",
hash_hex = siphash.hash_hex(key, message);
`

The 64-bit hash can also be obtained as two 32-bit values with
hash(key, message):

`javascript
var siphash = require("siphash"),
key = [ 0xdeadbeef, 0xcafebabe, 0x8badf00d, 0x1badb002 ],
message = "Short test message",
hash = siphash.hash(key, message),
hash_msb = hash.h,
hash_lsb = hash.l;
`

A 53-bit unsigned integer can be obtained with hash_uint(key, message):

`javascript
var siphash = require("siphash"),
key = siphash.string16_to_key("0123456789ABCDEF"),
message = "Short test message",
index = siphash.hash_uint(key, message);
``

SipHash-1-3
-----------
SipHash-1-3 is a faster variant of SipHash-2-4 with fewer rounds, which is still believed to be secure
enough for typical uses. This variant is available here:
siphash13.js

SipHash-double
--------------

Although not part of the module, an implementation of SipHash with
128-bit output is also available:
siphash-double.js

SipHash-1-3 with a 128-bit output is also part of the package:
siphash13-double.js