From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from sog-mx-4.v43.ch3.sourceforge.com ([172.29.43.194] helo=mx.sourceforge.net) by sfs-ml-4.v29.ch3.sourceforge.com with esmtp (Exim 4.76) (envelope-from ) id 1Vz93d-0002a4-6q for bitcoin-development@lists.sourceforge.net; Fri, 03 Jan 2014 18:01:17 +0000 X-ACL-Warn: Received: from mail-vc0-f174.google.com ([209.85.220.174]) by sog-mx-4.v43.ch3.sourceforge.com with esmtps (TLSv1:RC4-SHA:128) (Exim 4.76) id 1Vz93b-0004Bd-9c for bitcoin-development@lists.sourceforge.net; Fri, 03 Jan 2014 18:01:17 +0000 Received: by mail-vc0-f174.google.com with SMTP id if17so7485049vcb.33 for ; Fri, 03 Jan 2014 10:01:09 -0800 (PST) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20130820; h=x-gm-message-state:mime-version:from:date:message-id:subject:to :content-type; bh=lVN+ZUQycRgef6XGumW8hS3bWgZFRqG3ly6t6cLtibg=; b=CUcblh+3KiCnk0PrigR3T8DQKwZy/rbMZvBtkKToKTREQBzDIFhQi+G8Fhbu5szcO9 5aY/y5XQaiG405Ro61HTlTn210EtEg+iG1PnlSuaWJrYNoq4Key+l1vYWXFI66NA4fvi rKdr6VfjChkm1gDAfuKAfYE6hXAIdEMZ6ocV80HkV9Y76Li2jKGO3E2HLoAI7e0XlIR1 5ukkiwpLz85/KDeWxK28O6St7eYtc2yBWRimNU1PdY7maqBXSGdNcJKpgSBP5cTuDWC5 +irfPmAEc2MylbGVcGVb/Eye6N4l50K7lc6VgV3zBHkLenzvmWmSOuAsQzyaf+NX+RHv exjw== X-Gm-Message-State: ALoCoQlO5CSua3k5UzJDqnouL5B2H0O0sgBYBebgoNGjhWJjw74z20tgnOziNj1Mj6eLYZ+OnLKf X-Received: by 10.220.186.202 with SMTP id ct10mr53314783vcb.14.1388772069652; Fri, 03 Jan 2014 10:01:09 -0800 (PST) MIME-Version: 1.0 Received: by 10.52.245.98 with HTTP; Fri, 3 Jan 2014 10:00:49 -0800 (PST) X-Originating-IP: [84.228.227.229] From: Nadav Ivgi Date: Fri, 3 Jan 2014 20:00:49 +0200 Message-ID: To: bitcoin-development Content-Type: multipart/alternative; boundary=047d7b676fd0e300ca04ef14b1d0 X-Spam-Score: 1.1 (+) X-Spam-Report: Spam Filtering performed by mx.sourceforge.net. See http://spamassassin.org/tag/ for more details. 1.0 HTML_MESSAGE BODY: HTML included in message 0.1 DKIM_SIGNED Message has a DKIM or DK signature, not necessarily valid 0.0 T_DKIM_INVALID DKIM-Signature header exists but is not valid X-Headers-End: 1Vz93b-0004Bd-9c Subject: [Bitcoin-development] An idea for alternative payment scheme X-BeenThere: bitcoin-development@lists.sourceforge.net X-Mailman-Version: 2.1.9 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Fri, 03 Jan 2014 18:01:17 -0000 --047d7b676fd0e300ca04ef14b1d0 Content-Type: text/plain; charset=ISO-8859-1 I had an idea for a payment scheme that uses key derivation, but instead of the payee deriving the addresses, the payer would do it. It would work like that: 1. The payee publishes his master public key 2. The payer generates a random "receipt number" (say, 25 random bytes) 3. The payer derives an address from the master public key using the receipt number and pays to it 4. The payer sends the receipt to the payee 5. The payee derives a private key with that receipt and adds it to his wallet Advantages: - It increases privacy by avoiding address reuse - The process is asynchronous. The payee is completely passive in the payment process and isn't required to provide new addresses before each payment (so no payment server required) - Its usable as a replacement for cases where re-used addresses are the most viable solution (like putting an address in a forum signature or as a development fund in a github readme) - The receipt also acts as a proof of payment that the payer can provide to the payee - Also, if the master is known to belong to someone, this also allows the payer prove to a third-party that the payment was made to that someone. If the output was spent, it also proves that he was aware of the payment and has the receipt. - Its a really thin abstraction layer that doesn't require much changes Disadvantages: - Losing the receipt numbers means losing access to your funds, they are random and there's no way to restore them - It requires sending the receipt to the payee somehow. Email could work for that, but a better defined channel that also can talk to the Bitcoin client and add the receipt would be much better. What do you think? --047d7b676fd0e300ca04ef14b1d0 Content-Type: text/html; charset=ISO-8859-1 Content-Transfer-Encoding: quoted-printable
I had an idea for a payment scheme that uses key deri= vation, but instead of the payee deriving the addresses, the payer would do= it.

It would work like that:
  1. Th= e payee publishes his master public key
  2. The payer generates a random "receipt number" (say, 25 r= andom bytes)
  3. The payer derives an address from the master publi= c key using the receipt number and pays to it
  4. The payer sends t= he receipt to the payee
  5. The payee derives a private key with that receipt and adds it to h= is wallet

Advantages:
    =
  • It increases privacy by avoiding address reuse
  • The process = is asynchronous. The payee is completely passive in the payment process and= isn't required to provide new addresses before each payment (so no pay= ment server required)
  • Its usable as a replacement for cases where re-used addresses are = the most viable solution (like putting an address in a forum signature or a= s a development fund in a github readme)
  • The receipt also acts = as a proof of payment that the payer can provide to the payee
  • Also, if the master is known to belong to someone, this also allow= s the payer prove to a third-party that the payment was made to that someon= e. If the output was spent, it also proves that he was aware of the payment= and has the receipt.
  • Its a really thin abstraction layer that doesn't require much = changes
Disadvantages:
  • Losing the rec= eipt numbers means losing access to your funds, they are random and there&#= 39;s no way to restore them
  • It requires sending the receipt to the payee somehow. Email could = work for that, but a better defined channel that also can talk to the Bitco= in client and add the receipt would be much better.
What do you think?
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