Return-Path: Received: from smtp1.osuosl.org (smtp1.osuosl.org [140.211.166.138]) by lists.linuxfoundation.org (Postfix) with ESMTP id 20EF4C002D for ; Thu, 22 Sep 2022 03:07:04 +0000 (UTC) Received: from localhost (localhost [127.0.0.1]) by smtp1.osuosl.org (Postfix) with ESMTP id DA43582F4F for ; Thu, 22 Sep 2022 03:07:03 +0000 (UTC) DKIM-Filter: OpenDKIM Filter v2.11.0 smtp1.osuosl.org DA43582F4F Authentication-Results: smtp1.osuosl.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.a=rsa-sha256 header.s=20210112 header.b=eCcznNNF X-Virus-Scanned: amavisd-new at osuosl.org X-Spam-Flag: NO X-Spam-Score: -2.098 X-Spam-Level: X-Spam-Status: No, score=-2.098 tagged_above=-999 required=5 tests=[BAYES_00=-1.9, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, FREEMAIL_FROM=0.001, HTML_MESSAGE=0.001, RCVD_IN_DNSWL_NONE=-0.0001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001] autolearn=ham autolearn_force=no Received: from smtp1.osuosl.org ([127.0.0.1]) by localhost (smtp1.osuosl.org [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id TEPPePurUCmW for ; Thu, 22 Sep 2022 03:07:03 +0000 (UTC) X-Greylist: whitelisted by SQLgrey-1.8.0 DKIM-Filter: OpenDKIM Filter v2.11.0 smtp1.osuosl.org C0ECC82628 Received: from mail-qv1-xf2c.google.com (mail-qv1-xf2c.google.com [IPv6:2607:f8b0:4864:20::f2c]) by smtp1.osuosl.org (Postfix) with ESMTPS id C0ECC82628 for ; Thu, 22 Sep 2022 03:07:02 +0000 (UTC) Received: by mail-qv1-xf2c.google.com with SMTP id s13so5918882qvq.10 for ; Wed, 21 Sep 2022 20:07:02 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; h=to:subject:message-id:date:from:mime-version:from:to:cc:subject :date; bh=zipJCSn67B5g042fg1M1Emn8unssIC9sfS6dJj9NaGE=; b=eCcznNNFnzY+oi+xouRF05b/wkHYMfR5FdNd1X9gXNyrq4nziwfAwXUg4EZM/bBPB6 dCkiT1Ssz91E8lLtbrNjW7FevvN89N4Qn1BPJwHVqd2SAM+EotKxXUYR3VbY953VRl9r zvgluimAl0Q2C9LbYoQd/RTQDzlO6HXQpjRLJEOpYMSQ2hfAsWGULe7w7byVg4ghNlK/ VNXsCGOhNtF5R9J88+ThT2/4xSLTkH5AJyun3ph8XAoczihx/8Q9k97SjaD8CYCLvQL7 oLFCtTXgsYEmKdffo+24r3RErpeV5GDN3JXbIAe5AkZ5TpEi1c7HnMbGN8c2bgCY8nsR U0zg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=to:subject:message-id:date:from:mime-version:x-gm-message-state :from:to:cc:subject:date; bh=zipJCSn67B5g042fg1M1Emn8unssIC9sfS6dJj9NaGE=; b=tqsV5Zm6iwllb5i+GSEVPOHQZa1CJ8gnCPDU0Jf9YY8cM8LEjqWVgkk1UwdD1ziVlX sobFUkFS7gqY+Jbg78UT13AkjnQXB0R9lU0TivjErErpx2cPribPLu1xMSitlNJ9LHcg XBDuELDLhViWQSuXTjRf+2c00j9xEI24pgoTwfxjuJ3detBo0rTAm/9nobDtKQ4ZMAQ5 KTAnDmZtcsvFJyUy3HtbIBsHJvTXmC814mMd7YHxy0PRlS1FWTBMRwg1xvLQhVoU21YY ZTKZDrAYNHgF0h58s5N6L3s9m2GebfdoD5A30LSPRmAucjkVEnHWoT4kvpxfI3Yb51je aT3w== X-Gm-Message-State: ACrzQf33WiuURSeL0tTMASK+jcslxzTNZHLuKzMDRKUZossUFeg2AESo KWOS/oyic9oPv3+IS7DfEMV/GBk40EuxSVaTkplZHvi0 X-Google-Smtp-Source: AMsMyM4bGm+QoUFKpcgG4QWHMS8cJMuU7mCdXnQckmMrAKGXdvjdNtZ2HfuUcBJFETXMaXGm3zbtwC7N6rxfu2u/e+4= X-Received: by 2002:ad4:5cec:0:b0:4ac:96fc:24e3 with SMTP id iv12-20020ad45cec000000b004ac96fc24e3mr1013504qvb.95.1663816021416; Wed, 21 Sep 2022 20:07:01 -0700 (PDT) MIME-Version: 1.0 From: El_Hoy Date: Thu, 22 Sep 2022 00:06:50 -0300 Message-ID: To: Bitcoin DEV Content-Type: multipart/alternative; boundary="000000000000ed9ec505e93b5ad6" X-Mailman-Approved-At: Thu, 22 Sep 2022 15:17:57 +0000 Subject: [bitcoin-dev] RFC for a BIP32 recurrent address derivation scheme X-BeenThere: bitcoin-dev@lists.linuxfoundation.org X-Mailman-Version: 2.1.15 Precedence: list List-Id: Bitcoin Protocol Discussion List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Thu, 22 Sep 2022 03:07:04 -0000 --000000000000ed9ec505e93b5ad6 Content-Type: text/plain; charset="UTF-8" There is a known issue on bitcoin, that is that every transaction requires a new address to prevent address reuse, making it uncomfortable to make recurring payments, as every payment requires a new off-chain interaction. A scheme is already mentioned on the [on the BIP32 itself][1], but it cannot be implemented as is. Here I propose a scheme that follows the structure described on [BIP44] that should make it possible to send recurring payments using a single offline interaction. The proposed scheme is: master / purpose' / coin_type' / contact' / index Where the definitions of all the levels follow BIP44, except for `contact` that is described below. Example usage: Bob wants to make recurring payments to Carol, so he asks her for a _contact address_, that is, an extended public key. Bob can use that public key to generate multiple derived addresses to make multiple recurring payments to Carol, the contact address is stored off-chain, anyone inspecting the chain will just see normal transactions on-chain. ## Considerations [BIP47] tries to solve the same issue, but the solution is more complex and involves more on-chain transactions that involve data, this implementation simpler and requires less work to implement. Also, the derivation path might need some adjustments for different address types on bitcoin. Finally, this only works in a single direction and does not make it possible for Carol to send anything to Bob, as it would require Bob sending her a contact address. ## Advantages A positive side effect of using this, is that Bob can choose to send payments to Carol using multiple outputs, giving him more privacy. Also, those payments can be easily labeled by the receiving wallet, as they are received. Regards. ### References [1]: https://github.com/bitcoin/bips/blob/master/bip-0032.mediawiki#recurrent-business-to-business-transactions-nmih0 [BIP47]: https://github.com/bitcoin/bips/blob/master/bip-0047.mediawiki "Reusable Payment Codes for Hierarchical Deterministic Wallets" [BIP43]: https://github.com/bitcoin/bips/blob/master/bip-0043.mediawiki#Purpose --- Eloy --000000000000ed9ec505e93b5ad6 Content-Type: text/html; charset="UTF-8" Content-Transfer-Encoding: quoted-printable
There is a known issue on bitcoin, that is that every tran= saction requires a new address to prevent address reuse, making it uncomfor= table to make recurring payments, as every payment requires a new off-chain= interaction. A scheme is already mentioned on the [on the BIP32 itself][1]= , but it cannot be implemented as is.

Here I propose a scheme that f= ollows the structure described on [BIP44] that should make it possible to s= end recurring payments using a single offline interaction.

The propo= sed scheme is:

=C2=A0 =C2=A0 master / purpose' / coin_type' = / contact' / index

Where the definitions of all the levels follo= w BIP44, except for `contact` that is described below.

Example = usage: Bob wants to make recurring payments to Carol, so he asks her for a = _contact address_, that is, an extended public key.

Bob= can use that public key to generate multiple derived addresses to make mul= tiple recurring payments to Carol, the contact address is stored off-chain,= anyone inspecting the chain will just see normal transactions on-chain.

## Considerations

[BIP47] tri= es to solve the same issue, but the solution is more complex and involves m= ore on-chain transactions that involve data, this implementation simpler an= d requires less work to implement.

Also, the d= erivation path might need some adjustments for different address types on b= itcoin.

Finally, this only works in a single d= irection and does not make it possible for Carol to send anything to Bob, a= s it would require Bob sending her a contact address.

<= div>## Advantages

A positive side effect of using this, i= s that Bob can choose to send payments to Carol using multiple outputs, giv= ing him more privacy.

Also, those payments can be = easily labeled by the receiving wallet, as they are received.
Regards.

### References

<= div>[1]: https://github.c= om/bitcoin/bips/blob/master/bip-0032.mediawiki#recurrent-business-to-busine= ss-transactions-nmih0
[BIP47]: https://github.com/bitcoin/bips= /blob/master/bip-0047.mediawiki "Reusable Payment Codes for Hierar= chical Deterministic Wallets"
[BIP43]: https://github.com/b= itcoin/bips/blob/master/bip-0043.mediawiki#Purpose

--- Eloy --000000000000ed9ec505e93b5ad6--