From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from smtp3.osuosl.org (smtp3.osuosl.org [140.211.166.136]) by lists.linuxfoundation.org (Postfix) with ESMTP id 002B1C000A for ; Mon, 5 Apr 2021 00:28:19 +0000 (UTC) Received: from localhost (localhost [127.0.0.1]) by smtp3.osuosl.org (Postfix) with ESMTP id D99EC60873 for ; Mon, 5 Apr 2021 00:28:19 +0000 (UTC) X-Virus-Scanned: amavisd-new at osuosl.org X-Spam-Flag: NO X-Spam-Score: 0.602 X-Spam-Level: X-Spam-Status: No, score=0.602 tagged_above=-999 required=5 tests=[BAYES_50=0.8, 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 Authentication-Results: smtp3.osuosl.org (amavisd-new); dkim=pass (2048-bit key) header.d=gmail.com Received: from smtp3.osuosl.org ([127.0.0.1]) by localhost (smtp3.osuosl.org [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id gv243icfU7tW for ; Mon, 5 Apr 2021 00:28:18 +0000 (UTC) X-Greylist: whitelisted by SQLgrey-1.8.0 Received: from mail-pf1-x436.google.com (mail-pf1-x436.google.com [IPv6:2607:f8b0:4864:20::436]) by smtp3.osuosl.org (Postfix) with ESMTPS id BC4AD60872 for ; Mon, 5 Apr 2021 00:28:18 +0000 (UTC) Received: by mail-pf1-x436.google.com with SMTP id h3so2361323pfr.12 for ; Sun, 04 Apr 2021 17:28:18 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=PUgbhOJzsNfuLyzAFxYefPRrcG1bR/X7Y2VaKcGaUNM=; b=bkeLlpd97ly/2GXbRhZ53LenBxaQKUUSnHg7QIWHxFWZ6RM0uarCnLvWJmO2yFXN+/ eZ0GmCc+D218ZaUy0OasRZb7ld39vKa4u22Q7vu2m9aXTztbbCLDFxRuVNPq5a3LFkwW liHyOh/hnLfOR/V9b/lPRlaWoT1yQ1vBTIiw6AcW9gm5y2U4Vkr9RGemg/A3tkUvSHys 6sRZ9fxTYF0JkOn0tkcKOIKNXjYQ1csLEoHIy5ilM7jAhz03ZVofopyOPtUCfG+aKJSh s0eOmcopXMJ1sbMNGmrkGYYmehz685zm/OB2vSy3NjXrrdCDRkk+fmL/OD4YFbEiTfNS gjLg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=PUgbhOJzsNfuLyzAFxYefPRrcG1bR/X7Y2VaKcGaUNM=; b=ThaPIWMUWvGZtSb1PaG+ZrRiVM1vGowm7YTxxB8y2KYFnXhi31WQGYkY1BbZJb+sP1 XxbUk1SzUwhiSZAtyW2BrNH+FyO92uG5jG1vS+LwPxftQ55YKTfHESlSEflK9YWSqwo+ Tw0IhaQdg9s2EybSZJ4nA6LOh8R3QTyUERrUg/kWXZDcAWK398716ZYDBhYgLFr9ZMen 1LybiOnFVRcCtOkAxWF3WwZzWZLMjgdXqb1V/fPTGY7i+raE4e8zDGfC3Uce7jYjkx/G fXY8D2UTT42nBLYFwpQzfZRfgdjlLImO0pjbOFKvS9g7D0MoqMIFwtGkRm7snt8hsj2+ tIyg== X-Gm-Message-State: AOAM533plwxGbnzLKsYZ49CHjVD6WIKZLOLCCAeqDhCL3n6oLCgzQQAV 81XIue2yUMCqPb5IHE8k1yr8uTQEGJHk3V+HbWH171h9GlubRg== X-Google-Smtp-Source: ABdhPJyd5aPSv6P8JKWAi3qU2hirTfIDo8AL99+QILspGflZDLCoC6aP3TIwvkSgezC36dB5MxJ5x09zcpbbRov+ois= X-Received: by 2002:a65:5c88:: with SMTP id a8mr20365400pgt.130.1617582498074; Sun, 04 Apr 2021 17:28:18 -0700 (PDT) MIME-Version: 1.0 References: <202103152148.15477.luke@dashjr.org> <20210316002401.zlfbc3y2s7vbrh35@ganymede> In-Reply-To: <20210316002401.zlfbc3y2s7vbrh35@ganymede> From: Lloyd Fournier Date: Mon, 5 Apr 2021 10:27:50 +1000 Message-ID: To: "David A. Harding" , Bitcoin Protocol Discussion Content-Type: multipart/alternative; boundary="0000000000003151e305bf2ec668" X-Mailman-Approved-At: Mon, 05 Apr 2021 21:47:48 +0000 Subject: Re: [bitcoin-dev] PSA: Taproot loss of quantum protections 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: Mon, 05 Apr 2021 00:28:20 -0000 --0000000000003151e305bf2ec668 Content-Type: text/plain; charset="UTF-8" On Tue, 16 Mar 2021 at 11:25, David A. Harding via bitcoin-dev < bitcoin-dev@lists.linuxfoundation.org> wrote: > > I curious about whether anyone informed about ECC and QC > knows how to create output scripts with lower difficulty that could be > used to measure the progress of QC-based EC key cracking. E.g., > NUMS-based ECDSA- or taproot-compatible scripts with a security strength > equivalent to 80, 96, and 112 bit security. Hi Dave, This is actually relatively easy if you are willing to use a trusted setup. The trusted party takes a secp256k1 secret key and verifiably encrypt it under a NUMS public key from the weaker group. Therefore if you can crack the weaker group's public key you get the secp256k1 secret key. Camenisch-Damgard[1] cut-and-choose verifiable encryption works here. People then pay the secp256k1 public key funds to create the bounty. As long as the trusted party deletes the secret key afterwards the scheme is secure. Splitting the trusted setup among several parties where only one of them needs to be honest looks doable but would take some engineering and analysis work. [1] https://link.springer.com/content/pdf/10.1007/3-540-44448-3_25.pdf Cheers, LL --0000000000003151e305bf2ec668 Content-Type: text/html; charset="UTF-8" Content-Transfer-Encoding: quoted-printable
On Tue, 16 Mar 2021 = at 11:25, David A. Harding via bitcoin-dev <bitcoin-dev@lists.linuxfoundation.org> = wrote:

I curious about whether anyone informed about ECC and= QC
knows how to create output scripts with lower difficulty that could be
used to measure the progress of QC-based EC key cracking.=C2=A0 E.g.,
NUMS-based ECDSA- or taproot-compatible scripts with a security strength equivalent to 80, 96, and 112 bit security.

Hi Dave,

This is actually relatively easy if you = are willing to use a trusted setup. The trusted party takes a secp256k1 sec= ret key and verifiably encrypt it under a NUMS public key from the weaker g= roup. Therefore if you can crack the weaker group's public key you get = the secp256k1 secret key. Camenisch-Damgard[1] cut-and-choose verifiable en= cryption works here.
People then pay the secp256k1 public key fun= ds to create the bounty. As long as the trusted party deletes the secret ke= y afterwards the scheme is secure.

Splitting t= he trusted setup among several parties where only one of them needs to be h= onest looks doable but would take some engineering and analysis work.


Cheers,

=
LL
=C2=A0
--0000000000003151e305bf2ec668--