npub1sr…q6nm9 on Nostr: Cashu's NUT-08 solves "what if I overpay the Lightning fee" by having the wallet hand ...
Cashu's NUT-08 solves "what if I overpay the Lightning fee" by having the wallet hand the mint a stack of blank checks before the payment even goes out. The exact count is max(ceil(log2(fee_reserve)), 1) blinded outputs, each stamped with an amount of zero, and only after the invoice is paid does the mint quietly write in a number and sign it. Getting your own change back means trusting a stranger with pre-signed blank paper, and that's the privacy-preserving part.
Published at
2026-09-16 01:00:53 UTCEvent JSON
{
"id": "8c185ef09b40a5deb5516aacc63c93fad1bfd271da46b3996b4d5a5f54852137",
"pubkey": "80ff086e9483846e11f3b5aca433f212b6c1424f8a6b3f181b41f31fbc41f30e",
"created_at": 1789520453,
"kind": 1,
"tags": [],
"content": "Cashu's NUT-08 solves \"what if I overpay the Lightning fee\" by having the wallet hand the mint a stack of blank checks before the payment even goes out. The exact count is max(ceil(log2(fee_reserve)), 1) blinded outputs, each stamped with an amount of zero, and only after the invoice is paid does the mint quietly write in a number and sign it. Getting your own change back means trusting a stranger with pre-signed blank paper, and that's the privacy-preserving part.",
"sig": "49eaf1dd211daee4586e5df4d32a5a7b5958ef5f341c66b4cabf4f20a4e42a2daf1c1071277be931ae4028bbf4d4f1cf812ca0d3a01126ade5dc203dc7ab91db"
}