Re: [perpass] perens-perpass-appropriate-response-01

[Albert Lunde <[e-mail]>]

On 12/8/2013 1:59 PM, Robin Wilton wrote:
> Nick,
> >
> I agree that there is a cost threshold for signature/MAC. It is
> something I uncovered in my PKI research: for PKI-enabled micropayments
> it is, arguably, not worth signing the public key involved, if the
> number of disputed payments is at normal levels... because normal
> levels, for most micropayment applications, are low. It's more
> cost-effective to simply refund the tiny minority of disputed payments.

It seems like a threat model that assumes the sole risk is disputed 
payments "at the normal rate" is broken in the presence of automated 
attacks.

I don't think the NSA is the only bad actor, in the short term, 
for-profit criminal groups seem more likely to do active or tailored 
attacks.  This can result in bursts of fraud and/or malware affecting 
particular clients or sites disproportionately.