Received: from sog-mx-3.v43.ch3.sourceforge.com ([172.29.43.193] helo=mx.sourceforge.net) by sfs-ml-3.v29.ch3.sourceforge.com with esmtp (Exim 4.76) (envelope-from ) id 1WQxJ8-0002yM-IT for bitcoin-development@lists.sourceforge.net; Fri, 21 Mar 2014 11:08:14 +0000 Received-SPF: pass (sog-mx-3.v43.ch3.sourceforge.com: domain of gmail.com designates 209.85.214.182 as permitted sender) client-ip=209.85.214.182; envelope-from=mh.in.england@gmail.com; helo=mail-ob0-f182.google.com; Received: from mail-ob0-f182.google.com ([209.85.214.182]) by sog-mx-3.v43.ch3.sourceforge.com with esmtps (TLSv1:RC4-SHA:128) (Exim 4.76) id 1WQxJ7-0002Xh-KH for bitcoin-development@lists.sourceforge.net; Fri, 21 Mar 2014 11:08:14 +0000 Received: by mail-ob0-f182.google.com with SMTP id uz6so2294820obc.13 for ; Fri, 21 Mar 2014 04:08:08 -0700 (PDT) MIME-Version: 1.0 X-Received: by 10.182.241.67 with SMTP id wg3mr7636383obc.16.1395400088301; Fri, 21 Mar 2014 04:08:08 -0700 (PDT) Sender: mh.in.england@gmail.com Received: by 10.76.71.231 with HTTP; Fri, 21 Mar 2014 04:08:08 -0700 (PDT) In-Reply-To: <20140321105906.GA1725@netbook.cypherspace.org> References: <20140320121221.GA25052@netbook.cypherspace.org> <20140321105906.GA1725@netbook.cypherspace.org> Date: Fri, 21 Mar 2014 12:08:08 +0100 X-Google-Sender-Auth: UvYm6KRuV8YWjEVXX9E4iYOCXcE Message-ID: From: Mike Hearn To: Adam Back Content-Type: multipart/alternative; boundary=001a11c2efb89539ce04f51be6f5 X-Spam-Score: -0.5 (/) X-Spam-Report: Spam Filtering performed by mx.sourceforge.net. See http://spamassassin.org/tag/ for more details. -1.5 SPF_CHECK_PASS SPF reports sender host as permitted sender for sender-domain 0.0 FREEMAIL_FROM Sender email is commonly abused enduser mail provider (mh.in.england[at]gmail.com) -0.0 SPF_PASS SPF: sender matches SPF record 1.0 HTML_MESSAGE BODY: HTML included in message 0.1 DKIM_SIGNED Message has a DKIM or DK signature, not necessarily valid -0.1 DKIM_VALID Message has at least one valid DKIM or DK signature X-Headers-End: 1WQxJ7-0002Xh-KH Cc: Bitcoin Dev , Andreas Schildbach Subject: Re: [Bitcoin-development] Payment Protocol for Face-to-face Payments 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, 21 Mar 2014 11:08:14 -0000 --001a11c2efb89539ce04f51be6f5 Content-Type: text/plain; charset=UTF-8 On Fri, Mar 21, 2014 at 11:59 AM, Adam Back wrote: > Maybe its time to explore raw ECDSA signed message based certs. > If you want to create and run a new CA, by all means. But I bet you don't. So we're stuck with the current system for now. > btw I dont think its quite 4kB. eg bitpay's looks to be about 1.5kB in der > format. And they contain a 2048-bit RSA server key, and 2048-bit RSA > signatures (256byte each right there = 512bytes). And even 2048 is weaker > than 256-bit ECDSA. But you have to chain up to the root. The only reason more certs aren't ECC is backwards compatibility. Some old browsers don't know how to handle them. It wasn't so long ago that Fedora and Android were deleting ECC code from upstream libraries before shipping them, either for patent reasons for disk space saving measures. But it's possible to get ECC certs if you want. For example, Entrust is starting to sell them: http://www.entrust.net/ecc-certs/index.htm But their intermediate cert is still RSA. My understanding is that ECC roots for many CA's have been submitted and are now included, but of course "give up compatibility with lots of users" vs "save a bit of cpu time and a handful of bytes" is no real competition so it will be a long time until most websites are using ECC certs. Regardless, it's all irrelevant. Who knows when we might want to add another feature that uses some bytes into PaymentRequests. Stuffing them into a QR code will never make much sense IMO - it's far more sensible to just use Bluetooth where the data size constraints are so much easier. --001a11c2efb89539ce04f51be6f5 Content-Type: text/html; charset=UTF-8 Content-Transfer-Encoding: quoted-printable
On F= ri, Mar 21, 2014 at 11:59 AM, Adam Back <adam@cypherspace.org> wrote:
Maybe its time to explore raw ECDSA signed message based c= erts.

If you want to create and run a new CA, by= all means. But I bet you don't. So we're stuck with the current sy= stem for now.
=C2=A0
btw I dont think its quite 4kB. =C2=A0eg bitpay's looks to be about 1.5= kB in der
format. =C2=A0And they contain a 2048-bit RSA server key, and 2048-bit RSA<= br> signatures (256byte each right there =3D 512bytes). =C2=A0And even 2048 is = weaker
than 256-bit ECDSA.

But you have to chain u= p to the root.

The only reason more certs aren'= ;t ECC is backwards compatibility. Some old browsers don't know how to = handle them. It wasn't so long ago that Fedora and Android were deletin= g ECC code from upstream libraries before shipping them, either for patent = reasons for disk space saving measures.

But it's possible to get ECC certs if you want. For= example, Entrust is starting to sell them:


But their intermediate cert is still RSA. My unde= rstanding is that ECC roots for many CA's have been submitted and are n= ow included, but of course "give up compatibility with lots of users&q= uot; vs "save a bit of cpu time and a handful of bytes" is no rea= l competition so it will be a long time until most websites are using ECC c= erts.

Regardless, it's all irrelevant. Who knows when we = might want to add another feature that uses some bytes into PaymentRequests= . Stuffing them into a QR code will never make much sense IMO - it's fa= r more sensible to just use Bluetooth where the data size constraints are s= o much easier.
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