how slow are 4Kbit RSA keys? [was: Re: multiple keys vs multiple identities]

Grant Olson kgo at
Fri Sep 24 23:23:22 CEST 2010

On 9/24/10 4:29 PM, Daniel Kahn Gillmor wrote:
> My conclusion from the above data points is that if we're concerned
> about computational inefficiencies, 4096-bit RSA keys are not
> particularly bad offenders.
> Are there other interpretations of the above results?  does anyone else
> want to post comparable data points on different hardware?  How powerful
> is a typical smartphone anyway?  What kind of a cutoff are people
> willing to accept in terms of CPU cycles per signature validated?  or am
> i measuring the wrong thing entirely?

I can test on a Motorola i1 (Boost' droid) with APG, but I'll only be
able to do a stopwatch test.  As far as I'm concerned, under one sec is

I believe you've got a 4096 bit key that uses a serious hash.  Would you
mind posting a test clearsigned message so that we're all using the same
document to test against?


"I am gravely disappointed. Again you have made me unleash my dogs of war."

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