@scure/base
Advanced tools
Secure, audited & 0-dep implementation of base64, bech32, base58, base32 & base16
@scure/base is a JavaScript library that provides utilities for encoding and decoding data in various formats such as Base64, Base58, and Base16. It is designed to be lightweight and efficient, making it suitable for use in both browser and Node.js environments.
Base64 Encoding and Decoding
This feature allows you to encode and decode strings to and from Base64 format. It is useful for data serialization and transmission.
const { base64 } = require('@scure/base');
// Encoding a string to Base64
const encoded = base64.encode('Hello, World!');
console.log(encoded); // Outputs: 'SGVsbG8sIFdvcmxkIQ=='
// Decoding a Base64 string
const decoded = base64.decode(encoded);
console.log(decoded); // Outputs: 'Hello, World!'Base58 Encoding and Decoding
This feature allows you to encode and decode strings to and from Base58 format. Base58 is commonly used in cryptocurrencies for encoding addresses and keys.
const { base58 } = require('@scure/base');
// Encoding a string to Base58
const encoded = base58.encode('Hello, World!');
console.log(encoded); // Outputs: '72k1xXWG59wUsYvG'
// Decoding a Base58 string
const decoded = base58.decode(encoded);
console.log(decoded); // Outputs: 'Hello, World!'Base16 Encoding and Decoding
This feature allows you to encode and decode strings to and from Base16 (Hexadecimal) format. It is useful for representing binary data in a human-readable form.
const { base16 } = require('@scure/base');
// Encoding a string to Base16 (Hex)
const encoded = base16.encode('Hello, World!');
console.log(encoded); // Outputs: '48656c6c6f2c20576f726c6421'
// Decoding a Base16 (Hex) string
const decoded = base16.decode(encoded);
console.log(decoded); // Outputs: 'Hello, World!'base-x is a library for encoding and decoding data in various base formats, including Base58. It is similar to @scure/base in terms of functionality but focuses more on Base58 and other custom base encodings.
bs58 is a library specifically for Base58 encoding and decoding. It is highly optimized for performance and is commonly used in cryptocurrency applications. Unlike @scure/base, it does not support other base formats like Base64 or Base16.
base64-js is a library for Base64 encoding and decoding. It is lightweight and efficient, similar to @scure/base, but it only supports Base64 encoding and decoding.
Audited & minimal implementation of bech32, base64, base58, base32 & base16.
Check out Projects using scure-base.
scure — audited micro-libraries.
npm install @scure/base
deno add @scure/base
We support all major platforms and runtimes. The library is hybrid ESM / Common.js package.
import { base16, base32, base64, base58 } from '@scure/base';
// Flavors
import {
base58xmr,
base58xrp,
base32nopad,
base32hex,
base32hexnopad,
base32crockford,
base64nopad,
base64url,
base64urlnopad,
} from '@scure/base';
const data = Uint8Array.from([1, 2, 3]);
base64.decode(base64.encode(data));
// Convert utf8 string to Uint8Array
const data2 = new TextEncoder().encode('hello');
base58.encode(data2);
// Everything has the same API except for bech32 and base58check
base32.encode(data);
base16.encode(data);
base32hex.encode(data);
base58check is a special case: you need to pass sha256() function:
import { createBase58check } from '@scure/base';
createBase58check(sha256).encode(data);
Alternative API:
import { str, bytes } from '@scure/base';
const encoded = str('base64', data);
const data = bytes('base64', encoded);
We provide low-level bech32 operations. If you need high-level methods for BTC (addresses, and others), use scure-btc-signer instead.
Bitcoin addresses use both 5-bit words and bytes representations.
They can't be parsed using bech32.decodeToBytes. Instead, do something this:
const decoded = bech32.decode(address);
// NOTE: words in bitcoin addresses contain version as first element,
// with actual witness program words in rest
// BIP-141: The value of the first push is called the "version byte".
// The following byte vector pushed is called the "witness program".
const [version, ...dataW] = decoded.words;
const program = bech32.fromWords(dataW); // actual witness program
Same applies to Lightning Invoice Protocol
BOLT-11.
We have many tests in ./test/bip173.test.js that serve as minimal examples of
Bitcoin address and Lightning Invoice Protocol parsers.
Keep in mind that you'll need to verify the examples before using them in your code.
The code may feel unnecessarily complicated; but actually it's much easier to reason about. Any encoding library consists of two functions:
encode(A) -> B
decode(B) -> A
where X = decode(encode(X))
# encode(decode(X)) can be !== X!
# because decoding can normalize input
e.g.
base58checksum = {
encode(): {
// checksum
// radix conversion
// alphabet
},
decode(): {
// alphabet
// radix conversion
// checksum
}
}
But instead of creating two big functions for each specific case, we create them from tiny composable building blocks:
base58checksum = chain(checksum(), radix(), alphabet())
Which is the same as chain/pipe/sequence function in Functional Programming, but significantly more useful since it enforces same order of execution of encode/decode. Basically you only define encode (in declarative way) and get correct decode for free. So, instead of reasoning about two big functions you need only reason about primitives and encode chain. The design revealed obvious bug in older version of the lib, where xmr version of base58 had errors in decode's block processing.
Besides base-encodings, we can reuse the same approach with any encode/decode function
(bytes2number, bytes2u32, etc).
For example, you can easily encode entropy to mnemonic (BIP-39):
export function getCoder(wordlist: string[]) {
if (!Array.isArray(wordlist) || wordlist.length !== 2 ** 11 || typeof wordlist[0] !== 'string') {
throw new Error('Wordlist: expected array of 2048 strings');
}
return mbc.chain(mbu.checksum(1, checksum), mbu.radix2(11, true), mbu.alphabet(wordlist));
}
Uint8Array is represented as big-endian number:
[1, 2, 3, 4, 5] -> 1*(256**4) + 2*(256**3) 3*(256**2) + 4*(256**1) + 5*(256**0)
where 256 = 2**8 (8 bits per byte)
which is then converted to a number in another radix/base (16/32/58/64, etc).
However, generic conversion between bases has quadratic O(n^2) time complexity.
Which means base58 has quadratic time complexity too. Use base58 only when you have small constant sized input, because variable length sized input from user can cause DoS.
On the other hand, if both bases are power of same number (like 2**8 <-> 2**64),
there is linear algorithm. For now we have implementation for power-of-two bases only (radix2).
The library has been independently audited:
The library was initially developed for js-ethereum-cryptography.
At commit ae00e6d7,
it was extracted to a separate package called micro-base.
After the audit we've decided to use @scure NPM namespace for security.
MIT (c) Paul Miller (https://paulmillr.com), see LICENSE file.
FAQs
Secure, audited & 0-dep implementation of base64, bech32, base58, base32 & base16
We found that @scure/base demonstrated a healthy version release cadence and project activity because the last version was released less than a year ago. It has 1 open source maintainer collaborating on the project.
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