From owner-freebsd-security Mon May 17 3:16:18 1999 Delivered-To: freebsd-security@freebsd.org Received: from schuimpje.snt.utwente.nl (schuimpje.snt.utwente.nl [130.89.238.4]) by hub.freebsd.org (Postfix) with ESMTP id 01F7A14A2F for ; Mon, 17 May 1999 03:16:16 -0700 (PDT) (envelope-from jeroen@vangelderen.org) Received: from wit395301.student.utwente.nl ([130.89.235.121]:35597 "EHLO vangelderen.org" ident: "NO-IDENT-SERVICE[2]") by schuimpje.snt.utwente.nl with ESMTP id <8020-32302>; Mon, 17 May 1999 12:15:58 +0200 Message-ID: <373FEC63.D579485D@vangelderen.org> Date: Mon, 17 May 1999 12:16:03 +0200 From: "Jeroen C. van Gelderen" X-Mailer: Mozilla 4.51 [en] (Win98; U) X-Accept-Language: en MIME-Version: 1.0 To: Kris Kennaway Cc: Adam Shostack , nr1@ihug.co.nz, freebsd-security@FreeBSD.ORG Subject: Re: secure backup References: Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Sender: owner-freebsd-security@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.org Kris Kennaway wrote: > > On Sun, 16 May 1999, Adam Shostack wrote: > > > You're worried about errors on the tape, I presume? You could > > pipe the output of pgp through something that does redundant > > encoding, such that errors on the tape are recoverable outside > > the tape. There are some direct tradeoffs that you can find > > between bloat and recoverability; as you add bits, your odds > > of being able to reconstruct increase. > > Pipe the output of dump or tar or whatever you're using through > bdes(1). You don't need the overhead of PGP unless you want a > trusted third party to read the backup without knowing the > encryption key. PGP provides a password based encryption mode, just use that, you will still benefit from PGPs compression and checksumming facilities. > Pass the data through three > rounds of bdes doing an encrypt, decrypt, followed by encrypt (with different > keys, of course) and you've got yourself 3DES, which bdes doesn't seem to do > natively. Make the keys random, and stick those in a PGP file if you like. If you assume PGP is available, why not just use it? Using bdes(1) in this setup sounds way more complicated (thus error-prone) to me. > Transport the data stream to the server using ssh -c none (no need for the > overhead of another encryption layer unless you're really paranoid) Just being cautious is enough. Adding a layer of SSH encryption will at least twarth offline dictionary attacks on the backup passphrase. Encryption is cheap, why disable it if you don't have to? Cheers, Jeroen -- Jeroen C. van Gelderen - jeroen@vangelderen.org - 0xC33EDFDE To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-security" in the body of the message