From nobody Sat Jun 12 08:38:13 2021 Return-Path: X-Original-To: cbor@ietfa.amsl.com Delivered-To: cbor@ietfa.amsl.com Received: from localhost (localhost [127.0.0.1]) by ietfa.amsl.com (Postfix) with ESMTP id 5B2C93A1761; Sat, 12 Jun 2021 08:38:07 -0700 (PDT) X-Virus-Scanned: amavisd-new at amsl.com X-Spam-Flag: NO X-Spam-Score: -1.896 X-Spam-Level: X-Spam-Status: No, score=-1.896 tagged_above=-999 required=5 tests=[BAYES_00=-1.9, RCVD_IN_DNSWL_BLOCKED=0.001, SPF_FAIL=0.001, SPF_HELO_NONE=0.001, URIBL_BLOCKED=0.001] autolearn=no autolearn_force=no Received: from mail.ietf.org ([4.31.198.44]) by localhost (ietfa.amsl.com [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id U3Y1OCrbsUDH; Sat, 12 Jun 2021 08:38:03 -0700 (PDT) Received: from gabriel-2.zfn.uni-bremen.de (gabriel-2.zfn.uni-bremen.de [IPv6:2001:638:708:32::19]) (using TLSv1.2 with cipher ADH-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ietfa.amsl.com (Postfix) with ESMTPS id BCE013A1760; Sat, 12 Jun 2021 08:38:01 -0700 (PDT) Received: from [192.168.217.118] (p548dcc89.dip0.t-ipconnect.de [84.141.204.137]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by gabriel-2.zfn.uni-bremen.de (Postfix) with ESMTPSA id 4G2MKz3dsQz2xFp; Sat, 12 Jun 2021 17:37:59 +0200 (CEST) Content-Type: text/plain; charset=utf-8 Mime-Version: 1.0 (Mac OS X Mail 13.4 \(3608.120.23.2.7\)) From: Carsten Bormann In-Reply-To: <32952.1623509612@dooku> Date: Sat, 12 Jun 2021 17:37:59 +0200 Cc: cose@ietf.org, cbor@ietf.org X-Mao-Original-Outgoing-Id: 645205079.035338-2026f05e496eb776aec306fae7207e42 Content-Transfer-Encoding: quoted-printable Message-Id: References: <32952.1623509612@dooku> To: Michael Richardson X-Mailer: Apple Mail (2.3608.120.23.2.7) Archived-At: Subject: Re: [Cbor] [COSE] European Digital Health Certificates (used in European Digital Green Certificates = Vaccination certs) X-BeenThere: cbor@ietf.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: "Concise Binary Object Representation \(CBOR\)" List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Sat, 12 Jun 2021 15:38:07 -0000 On 2021-06-12, at 16:53, Michael Richardson = wrote: >=20 > My understanding is that QRcode can use the entire 8-bits. Am I = wrong? As usual, this is less about what QRcode *can* do (there is a nice = binary encoding in there), but about what you can get by all the broken = stuff that is out there. So the canonical way to handle this today is: (1) Use the =E2=80=9Calphanumeric=E2=80=9D 45-character set defined by = QR-Code specs as upper case letters + digits + space (!) + =C2=BB$%*+-./:=C2= =AB (2) Use all these characters =E2=80=94 even though 2**16**(1/3) is = 40.317473596635935 (45**3 =3D 91125, way more than 65536), so 41 out of = these characters would really suffice - don=E2=80=99t avoid the risky = characters. (3) Suffer. >> Maybe we can find someone to talk about practical aspects of DGC and >> related efforts at one of the next CBOR interims... >=20 > Actually, I think it belongs as a IAB Tech plenary talk. Not a bad idea, but probably requires significant preparation. Gr=C3=BC=C3=9Fe, Carsten