● PR opened for spontaneous LN payments: LN protocol developer Olaoluwa Osuntokun opened a pull request to allow an LN node to send a payment to another node without first receiving an invoice. This takes advantage of LN’s Tor-like onion routing by allowing a spender to choose a preimage, encrypt it so that only the receiver’s node can decrypt it, and then route a payment along LN like normal using the hash of the preimage. When the payment reaches the receiver, they decrypt the preimage and disclose it to the routing nodes in order to claim the payment.

Spontaneous payments help in cases where users just want to do ad hoc payment tracking, for example you initiate a 10 mBTC withdrawal from an exchange and either 10 mBTC shows up in your balance within a few moments or you contact support. Or you just publish your node’s information and users can send you donations without having to get an invoice first. For tracking specific payments, users should still continue to generate invoices which can be uniquely associated with particular orders or other expected payments.

Osuntokun’s pull request for LND is still marked as a work in progress as of this writing, so we don’t know yet when the feature will become generally available to LND users or whether other LN implementations will also provide the same feature in a compatible way.