“Does instant messaging over Lightning have killer application potential?”
Lightning Labs developer Joost Jager asked his Twitter followers this rhetorical when he debuted a demo for his Lightning Network messaging application, Whatsat.
Your average Bitcoiner probably wouldn’t think of messaging as one of Lightning’s killer use cases, at least not before micropayments, streaming payments and the like. For encrypted messaging, they’d likely default to options like Signal, Keybase or Wire.
These are certainly better than mainstream messaging apps, like Facebook’s Messenger and WhatsApp, whose encrypted options are thinly veiled save-faces that don’t offer much material confidentiality. But encrypted messaging needs to go further than privacy, Jager believes; they need censorship resistance too, and this is where Lightning-powered messaging comes in.
“The encryption part is similar, in both systems the message content is private,” Jager told Bitcoin Magazine. “The difference is that there is no central server involved. No single kill switch that could be used to shut down all communications. Or that is used more selectively to deny certain users to communicate.”
Whatsat: A New Approach to an Old Feature
The Lightning Network has supported messages from day one, same with Bitcoin’s base layer. The Blockstream Satellite has been used[1] in experiments around Lightning-driven messages and private text message services[2] have leveraged Lightning payments. But recent tweeks to the protocol[3] now make it easier to attach additional data to a payment and pass it on to other applications using type-length-value (TLV) payloads.
TLV payloads allow people using communication protocols to attach additional, extraneous information onto a data packet. For Whatsat, this extraneous data would be the message that is bolted onto a Lightning transaction.
The update that enabled TLV payloads paved the way for a concept like Whatsat which,
