broadcast-encryption

Distribute encryption keys to a dynamic set of receivers

Usage

const core = new Hypercore(storage)
const broadcast = new BroadcastEncryption(core, { keyPair })

const encryptionKey = Buffer.alloc(32)

// distribute key to everyone
await broadcast.update(encryptionKey, [peer1, peer2, peer3])

encryptionKey.fill(0xff) // update encryption key

// distribute new key to everyone except peer3
await broadcast.update(encryptionKey, [peer1, peer2])

await broadcast.get(id) // get the encryption key corresponding to id

API

const broadcast = new BroadcastEncryption(core, opts)

Instantiate a new broadcast instance.

opts include:

{
  keyPair, // receiver key pair used for decryption
  bootstrap // initial key information to use
}

const current = broadcast.id()

The current encryption key id.

await broadcast.update(key, recipients)

Distribute the updated key to all members of recipients.

const { id, encryptionKey } = await broadcast.get(id)

Get the encryption key corresponding to id.

If id is passed as -1, the latest encryption key shall be returned.

const encryption = await broadcast.createEncryptionProvider(opts)

Create a HypercoreEncryption provider to pass to a hypercore.

broadcast.on('update', (id) => {})

An update event is emitted when a new encryption key is loaded.

const payload = BroadcastEncryption.encrypt(data, recipients)

Static helper to broadcast encrypt a message.

const data = BroadcastEncryption.decrypt(payload, recipientSecretKey)

Static helper to decrypt a broadcast encrypted message.

const payload = BroadcastEncryption.verify(payload, data, recipients)

Static helper to verify a payload. Returns true if all members on recipients can decrypt data.

License

Apache-2.0