Trade night
Who is heavy
Put both sides on the table. The receipt gets a SHA-256 seal. The other person pastes it into their book. If a line changes, the seal fails. This does not move money and it does not write their vault from your phone.
Nothing in the book yet. Scan a card.
Your side
Their side
Even on the book. No cash.
You $0 · Them $0
Accept a seal