From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from sog-mx-1.v43.ch3.sourceforge.com ([172.29.43.191] helo=mx.sourceforge.net) by sfs-ml-1.v29.ch3.sourceforge.com with esmtp (Exim 4.76) (envelope-from ) id 1YIkba-0003iN-Sr for bitcoin-development@lists.sourceforge.net; Tue, 03 Feb 2015 21:01:54 +0000 Received-SPF: pass (sog-mx-1.v43.ch3.sourceforge.com: domain of gmail.com designates 74.125.82.45 as permitted sender) client-ip=74.125.82.45; envelope-from=mh.in.england@gmail.com; helo=mail-wg0-f45.google.com; Received: from mail-wg0-f45.google.com ([74.125.82.45]) by sog-mx-1.v43.ch3.sourceforge.com with esmtps (TLSv1:RC4-SHA:128) (Exim 4.76) id 1YIkbZ-0006EF-5Y for bitcoin-development@lists.sourceforge.net; Tue, 03 Feb 2015 21:01:54 +0000 Received: by mail-wg0-f45.google.com with SMTP id x12so46865283wgg.4 for ; Tue, 03 Feb 2015 13:01:47 -0800 (PST) MIME-Version: 1.0 X-Received: by 10.180.101.65 with SMTP id fe1mr16406250wib.66.1422997307117; Tue, 03 Feb 2015 13:01:47 -0800 (PST) Sender: mh.in.england@gmail.com Received: by 10.194.188.11 with HTTP; Tue, 3 Feb 2015 13:01:47 -0800 (PST) In-Reply-To: References: Date: Tue, 3 Feb 2015 22:01:47 +0100 X-Google-Sender-Auth: Hiiv9OwmNpMGiHlBJVjHQDggTkg Message-ID: From: Mike Hearn To: Adam Weiss Content-Type: multipart/alternative; boundary=f46d041826be01d8f0050e3561b5 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: 1YIkbZ-0006EF-5Y Cc: Bitcoin Dev , Will Subject: Re: [Bitcoin-development] Subject: Re: Proposal to address Bitcoin malware 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: Tue, 03 Feb 2015 21:01:54 -0000 --f46d041826be01d8f0050e3561b5 Content-Type: text/plain; charset=UTF-8 > > TREZOR like devices with BIP70 support and third party cosigning services > are a solution I really like the sound of. I suppose though that adding > BIP70 request signature validation and adding certificate revocation > support starts to balloon the scope of what is supposed to be a very simple > device though. > Yes, X.509 is ....... unfortunate. We'll have to wait and see how the TREZOR team get on with implementing it. TREZOR doesn't have any OS at all at the moment, so an implementation of PKIX will probably end up being larger than their existing codebase. That said, X.509 parsing is so security critical that the existing codebases for it are by now pretty robust. Touch wood. So just having a super stripped down OpenSSL implementation is probably good enough. W.R.T revocation, BIP70 doesn't support this. If your private key leaks you're currently hosed, identity wise, until the certificate expires. This is obviously suboptimal. In a world where we all have infinite time and resources the right fix will be to piggy back on an X.509 extension being proposed in the browser world called "Must Staple". It's a bit in the certificate flags that tell the client to expect a stapled OCSP response and to hard-fail if none is provided. By requesting the CA set this flag when you get your certificate issued, you sign up for more pain but more security. An OCSP stapling extension to BIP70 would probably not be very hard to implement, but it'd be pointless today because the client has no idea whether to expect it or not. The absence of a certificate changes the UI by showing you a random Bitcoin address instead of a human readable name, but the absence of stapled OCSP would not result in any UI change. > Regardless, I think a standard for passing partially signed transactions > around might make sense > I'm hoping that the hardware wallet world just standardises on the TREZOR protocol. It's well designed and these devices all have fairly similar capabilities. --f46d041826be01d8f0050e3561b5 Content-Type: text/html; charset=UTF-8 Content-Transfer-Encoding: quoted-printable
TREZOR like devices with BIP70 support and thir= d party cosigning services are a solution I really like the sound of.=C2=A0= I suppose though that adding BIP70 request signature validation and adding= certificate revocation support starts to balloon the scope of what is supp= osed to be a very simple device though.

Yes, X.509 is ....... unfortunate. We'll have to w= ait and see how the TREZOR team get on with implementing it. TREZOR doesn&#= 39;t have any OS at all at the moment, so an implementation of PKIX will pr= obably end up being larger than their existing codebase.=C2=A0
That said, X.509 parsing is so security critical that the exis= ting codebases for it are by now pretty robust. Touch wood. So just having = a super stripped down OpenSSL implementation is probably good enough.
=

W.R.T revocation, BIP70 doesn't support this. If yo= ur private key leaks you're currently hosed, identity wise, until the c= ertificate expires. This is obviously suboptimal. In a world where we all h= ave infinite time and resources the right fix will be to piggy back on an X= .509 extension being proposed in the browser world called "Must Staple= ". It's a bit in the certificate flags that tell the client to exp= ect a stapled OCSP response and to hard-fail if none is provided. By reques= ting the CA set this flag when you get your certificate issued, you sign up= for more pain but more security.

An OCSP stapling= extension to BIP70 would probably not be very hard to implement, but it= 9;d be pointless today because the client has no idea whether to expect it = or not. The absence of a certificate changes the UI by showing you a random= Bitcoin address instead of a human readable name, but the absence of stapl= ed OCSP would not result in any UI change.
=C2=A0
Regardless, I think a standard for passing partially = signed transactions around might make sense

I'm hoping that the hardware wallet world just= standardises on the TREZOR protocol. It's well designed and these devi= ces all have fairly similar capabilities.=C2=A0
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