Re: [rtcweb] Require/Suggest AEAD GCM for SRTP

Nils Ohlmeier <> Wed, 10 July 2019 18:25 UTC

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From: Nils Ohlmeier <>
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Date: Wed, 10 Jul 2019 11:25:41 -0700
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To: Sean DuBois <>
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Subject: Re: [rtcweb] Require/Suggest AEAD GCM for SRTP
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Hi Sean,

> On 10Jul, 2019, at 11:06, Sean DuBois <> wrote:
> Hello,
> I am Sean DuBois, I work on Pion [0] a 100% Go implementation of
> WebRTC. I have a user that is trying to do a large deployment, and
> performance is very important to them. They see a 10x performance
> improvement when using AEAD GCM for SRTP (thanks to HW acceleration)
> and is the most obvious improvement we can make.
> Having this would be a pretty fantastic improvement for very little
> work. Especially for weak devices/scaling servers, AES-NI is a huge
> deal. Also great for security, avoids possible timing attacks from
> software implementation and just less for developers can mess up when
> implementing SRTP themselves!
> This also should be pretty painless change.
> * FireFox already supports it
> * Chromium is just behind a flag [1]
> * Most other implementations also use libsrtp (where it is already available)
> * Adding more protection profiles will have zero impact if they aren't
> supported.
> ----
> I have never been involved with the IETF before, but this seems the
> best way to push implementations to support it.
> [0]
> [0]

As Firefox supports GCM already I’m in favor of adding it to the spec.

AFAIK GCM support in Chrome is behind a flag because they ran into some interop issues with early GCM implementations.

But it is pretty late in the standardization process to make/request such changes. I’ll leave it to other to judge this.

  Nils Ohlmeier