Return-Path: Received: from smtp1.linuxfoundation.org (smtp1.linux-foundation.org [172.17.192.35]) by mail.linuxfoundation.org (Postfix) with ESMTPS id E8323FF1 for ; Mon, 19 Feb 2018 20:12:18 +0000 (UTC) X-Greylist: whitelisted by SQLgrey-1.7.6 Received: from mail-wr0-f179.google.com (mail-wr0-f179.google.com [209.85.128.179]) by smtp1.linuxfoundation.org (Postfix) with ESMTPS id 3F9F8418 for ; Mon, 19 Feb 2018 20:12:18 +0000 (UTC) Received: by mail-wr0-f179.google.com with SMTP id f14so6445516wre.8 for ; Mon, 19 Feb 2018 12:12:18 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=mime-version:in-reply-to:references:from:date:message-id:subject:to; bh=cI9FzQRfO5j1ixH2mJRR19vq2QfMT11sSNVJqAbXGbA=; b=DGYRf/1h3BBWb7fofpeeg+0kC1HqEZ9SRfXrUAg3rMbY/PRQCHNLQwp89SBsrRiFtX /tAMcOLuAQ0yhvFSgArUB2K3o1annfIRJClM/yg+9m0cALFJ/pkYU2hfYtdGa+EqXlP/ OpVBqcykBLwTm5YTj7TwVBhARbjuXO+gTT0v2xTAUoYxGfDWeWjOEoph2KBa0SjqFv5P n15ssPdKk759NLlqMvBbFHJX5lJww1Xf7koSNDzqW9AxoQzH39GmICrJatBauU6pohZC PGmTB0rNzliOYRGxnVRB8IpgGen1kTifZ3BLgeGYh5K4Dp5yKXBtHA/mFv9Kr2/6q+l0 AYBg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:in-reply-to:references:from:date :message-id:subject:to; bh=cI9FzQRfO5j1ixH2mJRR19vq2QfMT11sSNVJqAbXGbA=; b=t08MwogI8GkAVjIwdy3/ohpg5m4BOClOUBAlKYXTyw259p4VlT8+tU+qVuQy+GvmnP aIPzS0pjSjcuX0R8GsJ+sRhsq9b3zTYle336xFKObP1uuWomRUH+EWv8PL42Od7WE/cf Lalpq8m2dJaER+gKmoj3RFuikyzkIdivJ7G6RK9DfAOGqrMjcxqg4M4XAZ3llyUIxzvp PjaEfguyGyKRxpQ8UCpR8HC7q9BkLM216MDdvro7Ua533wqudqDkZUCLcAY3HggcTuO9 T+yJsE8zZVdTYblrUpvJAnQagUmLR9M0vvJIi9hoF/cozTDWF7jIeAJBD87aewCE0U5E 6hOg== X-Gm-Message-State: APf1xPBnjS4Y/VGVFA8W1aHFA7Hk+eprXWx7uW12LHJSi+vgQQ9T6qpk iae5Gnrv1kcYzNgsxEANYOnTtElyBxuGOCLs8f4= X-Google-Smtp-Source: AH8x224OJLmZ9t1XXQsuBiZ3xSoS3lSj3rxKdi7yb9jY6GvSCwNuYOkoqN3aNKi2UmWMfyMzxdBwaGqicdsAvl/JmU0= X-Received: by 10.223.164.153 with SMTP id g25mr7695726wrb.79.1519071136670; Mon, 19 Feb 2018 12:12:16 -0800 (PST) MIME-Version: 1.0 Received: by 10.28.210.198 with HTTP; Mon, 19 Feb 2018 12:11:56 -0800 (PST) In-Reply-To: References: From: Lucas Clemente Vella Date: Mon, 19 Feb 2018 17:11:56 -0300 Message-ID: To: Ilan Oh , Bitcoin Protocol Discussion Content-Type: text/plain; charset="UTF-8" X-Spam-Status: No, score=-2.0 required=5.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID, DKIM_VALID_AU, FREEMAIL_FROM, RCVD_IN_DNSWL_NONE autolearn=ham version=3.3.1 X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on smtp1.linux-foundation.org X-Mailman-Approved-At: Mon, 19 Feb 2018 21:40:19 +0000 Subject: Re: [bitcoin-dev] Built in encryption X-BeenThere: bitcoin-dev@lists.linuxfoundation.org X-Mailman-Version: 2.1.12 Precedence: list List-Id: Bitcoin Protocol Discussion List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Mon, 19 Feb 2018 20:12:19 -0000 Theoretically, if the recipient address had already disclosed the public key (i.e. already spent from that address), or shared it with you instead of (or alongside with) the address, then you can use recipient's ECDSA key to encrypt the message with ECC, as both ECDSA and ECC share the same kind of public/private key pair, according to the this link: https://crypto.stackexchange.com/questions/14662/using-ecdsa-keys-for-encryption In practice, I am not sure the nodes would broadcast such non-standard transaction (but it can be mined, nonetheless). 2018-02-19 6:21 GMT-03:00 Ilan Oh via bitcoin-dev : > Hey guys, > > Features info, > I know we can add text to a btc transaction and it is pretty easy, > > However is it possible to encrypt the data in a way that only the receiver > would be able to read it in clear. > And of course without having to exchange info off the network. > > And if not possible on bitcoin would it be possible on a sidechain or on rsk > or else > > I have few ideas of concrete uses of it, I'm sure you guys may also think of > something interesting, > > Thanks, > > _______________________________________________ > bitcoin-dev mailing list > bitcoin-dev@lists.linuxfoundation.org > https://lists.linuxfoundation.org/mailman/listinfo/bitcoin-dev > -- Lucas Clemente Vella lvella@gmail.com