Re: [TLS] Encrypt-then-MAC again (was Re: padding bug)
Alfredo Pironti <alfredo@pironti.eu> Sat, 30 November 2013 18:23 UTC
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Date: Sat, 30 Nov 2013 19:23:53 +0100
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From: Alfredo Pironti <alfredo@pironti.eu>
To: Watson Ladd <watsonbladd@gmail.com>
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Subject: Re: [TLS] Encrypt-then-MAC again (was Re: padding bug)
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On Sat, Nov 30, 2013 at 7:02 PM, Watson Ladd <watsonbladd@gmail.com> wrote: > On Sat, Nov 30, 2013 at 9:58 AM, Alfredo Pironti <alfredo@pironti.eu> wrote: >> Hi Kenny, >> >>> But, at the risk of repeating myself, I very much prefer the simplicity >>> and robustness of an Encrypt-then-MAC construction. >> >> I agree with you. Indeed, Encrypt-then-MAC and (or within) AEAD are >> the only two cipher modes I'd like to see in TLS 1.3. > You do realize EtM is an AEAD if properly designed? I do. I was just speaking in TLS1.2 terminology, which does make a distinction, even though all schemes are supposed to deliver Authenticated Encryption with Additional Data anyway. If I just said that I only wanted AEAD, somebody else would have shoot at me instead by saying that GCM is too inefficient. >> >> In practice however, we witness the disastrous experience in widely >> deploying any change which is not a small patch to TLS1.0. So I'm >> afraid that to get something deployed in reasonable times we may have >> to get content with such a patch, like pad-MAC-Encrypt, that makes >> more robust (if not provably secure) what we already have. > How is pad-MAC-Encrypt less of a change then Encrypt then MAC? It is easier enough in that 2 implementations already implement pad-MtE (GnuTLS and miTLS), and my personal experience in implementing the patch says it's a small change. But we need even more factual feedback, and I hope we get more people to try to implement it elsewhere. > We still can't kill RC4, which is a *configuration change*. > Patches aren't getting deployed even if painless, so arguing about the > ease of deployment is a red herring. >> >> Alfredo > > > > -- > "Those who would give up Essential Liberty to purchase a little > Temporary Safety deserve neither Liberty nor Safety." > -- Benjamin Franklin
- Re: [TLS] Encrypt-then-MAC again (was Re: padding… Martin Rex
- Re: [TLS] Encrypt-then-MAC again (was Re: padding… Peter Gutmann
- Re: [TLS] Encrypt-then-MAC again (was Re: padding… Eric Rescorla
- Re: [TLS] Encrypt-then-MAC again (was Re: padding… Watson Ladd
- Re: [TLS] Encrypt-then-MAC again (was Re: padding… Juho Vähä-Herttua
- Re: [TLS] Encrypt-then-MAC again (was Re: padding… Bodo Moeller
- Re: [TLS] Encrypt-then-MAC again (was Re: padding… Nikos Mavrogiannopoulos
- Re: [TLS] Encrypt-then-MAC again (was Re: padding… Bodo Moeller
- Re: [TLS] Encrypt-then-MAC again (was Re: padding… Martin Rex
- Re: [TLS] Encrypt-then-MAC again (was Re: padding… Juho Vähä-Herttua
- Re: [TLS] Encrypt-then-MAC again (was Re: padding… Robert Ransom
- Re: [TLS] Encrypt-then-MAC again (was Re: padding… Nikos Mavrogiannopoulos
- Re: [TLS] Encrypt-then-MAC again (was Re: padding… Watson Ladd
- Re: [TLS] Encrypt-then-MAC again (was Re: padding… Juho Vähä-Herttua
- Re: [TLS] Encrypt-then-MAC again (was Re: padding… Martin Rex
- Re: [TLS] Encrypt-then-MAC again (was Re: padding… Taylor Hornby
- Re: [TLS] Encrypt-then-MAC again (was Re: padding… Martin Rex
- Re: [TLS] Encrypt-then-MAC again (was Re: padding… Nikos Mavrogiannopoulos
- Re: [TLS] Encrypt-then-MAC again (was Re: padding… Watson Ladd
- Re: [TLS] Encrypt-then-MAC again (was Re: padding… Martin Rex
- Re: [TLS] Encrypt-then-MAC again (was Re: padding… Nikos Mavrogiannopoulos
- Re: [TLS] Encrypt-then-MAC again (was Re: padding… Alfredo Pironti
- Re: [TLS] Encrypt-then-MAC again (was Re: padding… Paterson, Kenny
- Re: [TLS] Encrypt-then-MAC again (was Re: padding… Alfredo Pironti
- Re: [TLS] Encrypt-then-MAC again (was Re: padding… Watson Ladd
- Re: [TLS] Encrypt-then-MAC again (was Re: padding… Alfredo Pironti
- Re: [TLS] Encrypt-then-MAC again (was Re: padding… Martin Rex
- Re: [TLS] Encrypt-then-MAC again (was Re: padding… Wan-Teh Chang
- Re: [TLS] Encrypt-then-MAC again (was Re: padding… Paterson, Kenny
- Re: [TLS] Encrypt-then-MAC again (was Re: padding… Nikos Mavrogiannopoulos
- Re: [TLS] Encrypt-then-MAC again (was Re: padding… Paterson, Kenny
- Re: [TLS] Encrypt-then-MAC again (was Re: padding… Watson Ladd
- Re: [TLS] Encrypt-then-MAC again (was Re: padding… Martin Rex
- Re: [TLS] Encrypt-then-MAC again (was Re: padding… Peter Gutmann
- Re: [TLS] Encrypt-then-MAC again (was Re: padding… Peter Gutmann
- Re: [TLS] Encrypt-then-MAC again (was Re: padding… Peter Gutmann
- Re: [TLS] Encrypt-then-MAC again (was Re: padding… Peter Gutmann
- Re: [TLS] Encrypt-then-MAC again (was Re: padding… Trevor Perrin
- Re: [TLS] Encrypt-then-MAC again (was Re: padding… Watson Ladd