Re: [TLS] TLS client puzzles

Kyle Rose <> Wed, 06 July 2016 20:34 UTC

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From: Kyle Rose <>
Date: Wed, 06 Jul 2016 16:34:37 -0400
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To: Hannes Tschofenig <>
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Cc: "<>" <>, Dmitry Khovratovich <>
Subject: Re: [TLS] TLS client puzzles
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On Wed, Jul 6, 2016 at 4:23 PM, Hannes Tschofenig <
> wrote:

> the question for me is whether it will be an effective mechanism when
> many devices just do not support it (for a number of reasons)? For IoT
> devices the reason is simple: they don't have MBs of memory.
> Even the regular puzzle technique has the problem that you have to
> adjust the puzzle difficulty and what is a piece of cake for a desktop
> computer kills the battery of an IoT device.
> (And note that I am not saying that IoT devices aren't used for DDoS
> attacks.)

The point I was making earlier was simply that many web properties have
client population profiles that are overwhelmingly web browsers, and others
that are overwhelmingly IoT devices: client puzzles might be helpful on the
former, and useless on the latter. Objections that "IoT devices can't
handle client puzzles" doesn't apply to web properties with a web browser
client profile: it's like arguing that liver tastes bad when presented with
strawberry shortcake: yeah, that might be true... but it's not relevant.