From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id DD138C433F5 for ; Sun, 1 May 2022 18:38:54 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender: Content-Transfer-Encoding:Content-Type:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:In-Reply-To:MIME-Version:References: Message-ID:Subject:Cc:To:From:Date:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=MhkgC0nJbP3F0BTK1bfwCJC9AWlxEWutp+wpw/UnsZQ=; b=nLLPAKwYhQ/IvE XVHToP9gA4ROcYpktl9YohOppelsI0Er4t+4zYXpk0tRUYhwcJU/dZkBX1lmH2AnRZi7ji+dNEs9M SFYLSv9NeVa+mCZvRn+FGkr1ab3bQh/wjOl8kwHLPAhK9w9vInn9EOqOWe9Skuljc6c5VeYhAtte8 x8SPUlrCALammcwJFWZV6pWRrPNyy2ARSpt3Axlazk8PjYsgwNQ9hiZKLOpeuOTO3AyPWQ4geUpfo MxDW1xIv/RWxs21mH0jbms1utQy0ORXl2o1AYL/GFCcQHVh7FKSE+Q9wZ6FJJXbF1EtxGbS3NC+Zb ex2qrrUkvbcBfkX96ZQQ==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1nlES1-00GiiL-IV; Sun, 01 May 2022 18:37:45 +0000 Received: from dfw.source.kernel.org ([139.178.84.217]) by bombadil.infradead.org with esmtps (Exim 4.94.2 #2 (Red Hat Linux)) id 1nlERz-00Gihp-1z for linux-arm-kernel@lists.infradead.org; Sun, 01 May 2022 18:37:44 +0000 Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id 8105360FCE; Sun, 1 May 2022 18:37:42 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 9D2C1C385AA; Sun, 1 May 2022 18:37:41 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1651430261; bh=RPbPn+ISgi6eo/0pALloybPyhv8zLJjGIiCsUz+5jkk=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=l8KY085q1j58kNDn77EfgNTUs/QW0NgRLHFFsrP70fW6MmTc6/JdfQiu/IQDCeky0 Cd0zw5xxLmwosLTatvZDFiZ70aChyt+d9oRVmUmr+putbgNm/AAaRYCVURBNWAZ6+m XR3XQEFxGyL+j3oTqW8DLTjCZtFm73uP1G7w2C5yH6KZtCVLIKZEn/ps/xgjAe3qCq g0SSoWzlGJre074JiIH7Vv+FTjp8nwYBgkvO1ff6/y2zlgISwJfrKUsFOahBIU8faJ 8sz23MUwla1t6MVsU8klN9+K+k82xonNg06E4/rInHi+taPPiViGe24wUH9a6ueszP Ud5hxAYzA6jFw== Date: Sun, 1 May 2022 11:37:40 -0700 From: Eric Biggers To: Nathan Huckleberry Cc: linux-crypto@vger.kernel.org, linux-fscrypt@vger.kernel.org, Herbert Xu , "David S. Miller" , linux-arm-kernel@lists.infradead.org, Paul Crowley , Sami Tolvanen , Ard Biesheuvel Subject: Re: [PATCH v5 8/8] fscrypt: Add HCTR2 support for filename encryption Message-ID: References: <20220427003759.1115361-1-nhuck@google.com> <20220427003759.1115361-9-nhuck@google.com> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <20220427003759.1115361-9-nhuck@google.com> X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20220501_113743_176728_D99E81EF X-CRM114-Status: GOOD ( 13.78 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org On Wed, Apr 27, 2022 at 12:37:59AM +0000, Nathan Huckleberry wrote: > HCTR2 is a tweakable, length-preserving encryption mode that is intended > for use on CPUs with dedicated crypto instructions. HCTR2 has the > property that a bitflip in the plaintext changes the entire ciphertext. > This property fixes a known weakness with filename encryption: when two > filenames in the same directory share a prefix of >= 16 bytes, with > AES-CTS-CBC their encrypted filenames share a common substring, leaking > information. HCTR2 does not have this problem. > > More information on HCTR2 can be found here: "Length-preserving > encryption with HCTR2": https://eprint.iacr.org/2021/1441.pdf > > Signed-off-by: Nathan Huckleberry > Reviewed-by: Ard Biesheuvel Acked-by: Eric Biggers - Eric _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel