Ask HN: How would you prove you sent a payment on someone else's behalf?
Let&#x27;s say that Alice wants to give Bob some money but she doesn&#x27;t want Bob to know who it came from.  Alice can only send money in the form of physical paper checks.  Alice asks you to pay Bob for her and she writes you a check for the amount she wants you to give to Bob.<p>How could you prove to Alice that you did in fact send the requested amount to Bob? A legal proof would be acceptable (i.e. would a contract and&#x2F;or receipt suffice?), although if it&#x27;s logically and mathematically air-tight that would be best.