From nobody Mon Dec 19 23:17:19 2022 Return-Path: X-Original-To: privacy-pass@ietfa.amsl.com Delivered-To: privacy-pass@ietfa.amsl.com Received: from localhost (localhost [127.0.0.1]) by ietfa.amsl.com (Postfix) with ESMTP id 7FB88C1524A9 for ; Mon, 19 Dec 2022 23:17:18 -0800 (PST) X-Virus-Scanned: amavisd-new at amsl.com X-Spam-Flag: NO X-Spam-Score: -2.798 X-Spam-Level: X-Spam-Status: No, score=-2.798 tagged_above=-999 required=5 tests=[BAYES_00=-1.9, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_DNSWL_LOW=-0.7, RCVD_IN_ZEN_BLOCKED_OPENDNS=0.001, SPF_PASS=-0.001, URIBL_DBL_BLOCKED_OPENDNS=0.001, URIBL_ZEN_BLOCKED_OPENDNS=0.001] autolearn=ham autolearn_force=no Authentication-Results: ietfa.amsl.com (amavisd-new); dkim=pass (2048-bit key) header.d=lowentropy.net header.b=LQ6ZeodO; dkim=pass (2048-bit key) header.d=messagingengine.com header.b=LnO+JSRU Received: from mail.ietf.org ([50.223.129.194]) by localhost (ietfa.amsl.com [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id sACGUXjWvEcj for ; Mon, 19 Dec 2022 23:17:14 -0800 (PST) Received: from out5-smtp.messagingengine.com (out5-smtp.messagingengine.com [66.111.4.29]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by ietfa.amsl.com (Postfix) with ESMTPS id A7D9DC1516F4 for ; Mon, 19 Dec 2022 23:16:17 -0800 (PST) Received: from compute6.internal (compute6.nyi.internal [10.202.2.47]) by mailout.nyi.internal (Postfix) with ESMTP id 7C33D5C00BD for ; Tue, 20 Dec 2022 02:16:16 -0500 (EST) Received: from imap41 ([10.202.2.91]) by compute6.internal (MEProxy); Tue, 20 Dec 2022 02:16:16 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=lowentropy.net; h=cc:content-type:date:date:from:from:in-reply-to:message-id :mime-version:reply-to:sender:subject:subject:to:to; s=fm3; t= 1671520576; x=1671606976; bh=FU/HwL33R5BGOLtl3AwrBKTRQN7rDR3PZFf fkhJaazs=; b=LQ6ZeodOmuPncNKzNsD2D5qwk39uY/UyeKkxkc1sTNyKvIB4ZFj GzVMKaHpGWpfFqB7ee1I8X9iTESCYnRN65q8sIzauG/5rydIIT8hLLemNjaWCFRW cjVq69zNYpX+0hcHKP7e1hxIbnqvQw12ljqfcQhP7U6t3YVcLRftOFe2j7eeeaZl 8DYNOhGzmVE1bqjhuWKTi2/ZPT8RCP2xn3sPY/l1M0g/MkKrGEuripSW2xgcLh9q WVhzgHVhhI0+VO8D/WJlEpn3MuoJIEZZ/Ddvx10ZZqA7OMVWJqfnLgg/pCOkMuxT IpLM2oklCZKxocdrVLz+9TlVMo0AhVzowjw== DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d= messagingengine.com; h=cc:content-type:date:date:feedback-id :feedback-id:from:from:in-reply-to:message-id:mime-version :reply-to:sender:subject:subject:to:to:x-me-proxy:x-me-proxy :x-me-sender:x-me-sender:x-sasl-enc; s=fm2; t=1671520576; x= 1671606976; bh=FU/HwL33R5BGOLtl3AwrBKTRQN7rDR3PZFffkhJaazs=; b=L nO+JSRUtMDQ8MnxKVwRZhiv8kVBOVIkDeoJY+lxlhWFR2TinMbJe97siuJmGaXxX 9q0xUGaYuka77mdzo+pGKliR7XC4hNE3cP65mwH0p1+QEk//o1WBvvRg+ZhFknSw ESHZHnJ6JaPgGEqusfGhdBX8a0785a4MupODB/a2gCLx8lyY8ZjfZMDCGMQiaWx+ ZAPLqstUrprclYxE+frCP6CZNiC8RmPNdMNxPty5iupFOUQRjfU9ttyZd4Wr6ab/ UwG77J8qhwJCg0jFNrLcEi+l5KCUNWHBQvAqsF132KoLf1V690bPxe3nZZkpntJt 9rEluzDdCgnX4VhXU6zwQ== X-ME-Sender: X-ME-Proxy-Cause: gggruggvucftvghtrhhoucdtuddrgedvhedrgeeggddutdeiucetufdoteggodetrfdotf fvucfrrhhofhhilhgvmecuhfgrshhtofgrihhlpdfqfgfvpdfurfetoffkrfgpnffqhgen uceurghilhhouhhtmecufedttdenucenucfjughrpefofgggkfffhffvufgtsehttdertd erredtnecuhfhrohhmpedfofgrrhhtihhnucfvhhhomhhsohhnfdcuoehmtheslhhofigv nhhtrhhophihrdhnvghtqeenucggtffrrghtthgvrhhnpeegueehueejvdeiveffhedvke egffekgffgtdetleefkeeffedtjefhtdduvddutdenucffohhmrghinhepghhithhhuhgs rdgtohhmnecuvehluhhsthgvrhfuihiivgeptdenucfrrghrrghmpehmrghilhhfrhhomh epmhhtsehlohifvghnthhrohhphidrnhgvth X-ME-Proxy: Feedback-ID: ic129442d:Fastmail Received: by mailuser.nyi.internal (Postfix, from userid 501) id 36716234007B; Tue, 20 Dec 2022 02:16:16 -0500 (EST) X-Mailer: MessagingEngine.com Webmail Interface User-Agent: Cyrus-JMAP/3.7.0-alpha0-1185-g841157300a-fm-20221208.002-g84115730 Mime-Version: 1.0 Message-Id: <32fdefb9-359c-4b77-b645-8acd1d5f07c2@betaapp.fastmail.com> Date: Tue, 20 Dec 2022 18:16:07 +1100 From: "Martin Thomson" To: privacy-pass@ietf.org Content-Type: text/plain Archived-At: Subject: [Privacy-pass] Late late late architecture comments X-BeenThere: privacy-pass@ietf.org X-Mailman-Version: 2.1.39 Precedence: list List-Id: Privacy Pass Protocol List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Tue, 20 Dec 2022 07:17:18 -0000 Hey folks, I didn't do my homework on the privacy pass architecture document during the two WGLCs. I spent a little time on it today and have opened a few issues. Of note: 1. I think that there is an attack on the unlinkability properties that is fairly trivial to mount between a colluding Issuer and Origin. The document does disclaim responsibility for any collusion between Attester and Origin [1], but I'm not sure that that is a realistic constraint given what I'm seeing of the deployment context. https://github.com/ietf-wg-privacypass/base-drafts/issues/307 2. The idea that a Client might cache tokens and make them available to multiple Origins is a bit of a surprise. https://github.com/ietf-wg-privacypass/base-drafts/issues/308 I've opened issues for a few other things. [1] ...at least as far as the deployments go, the fully-shared model can't work that way, so that is confusing.