cryptomancy-shard

Cryptomancy-shard

For secret-sharing schemes which need support for threshold recombination there's cryptomancy-secret. If your needs are incredibly simple, this module may provide a simpler option.

Its goal is to be:

• small
• fast
• flexible
• readable
• secure

It's missing:

• threshold support
• authentication
• padding bytes

Use

// the API takes and outputs Uint8Arrays
// so you'll probably want to convert between that and different formats
var Format = require("cryptomancy-format");

// it expects you to supply your own randomness
// so it can be deterministic if that suits your needs
// otherwise use a cryptographically secure source of random bytes
var Source = require("cryptomancy-source");
var secure_bytes = Source.bytes.secure();

var plaintext = "PEW PEW PEW";
var u8_message = Format.decodeUTF8(plaintext);

// load the library
var Shard = require("cryptomancy-shard");

// split the plaintext up into 5 shards
// all of which are necessary to reproduce the original value
var shards = Shard.split(secure_bytes, u8_message, 5);

// print out your shards in whatever format you like
// I like base64 because they're probably not valid UTF8
// and I don't like hex
console.log(shards.map(Format.encode64));

// join the shards
// order doesn't matter because internally it's just xor'ing the values
var recovered = Format.encodeUTF8(Shard.join(shards));

console.log(recovered);