On 2013/07/22 (Jul), at 11:01 AM, Victor Denisov wrote: > If I'm correct and an attacker will > need to roughly match the network size for a successful attack, then > matching a network of 100K nodes, each of which had paid, say, $5 to > join, would require $500K - heck, even I, being a (relatively) poor > scientist, would probably be able to raise that money in a couple of > months (by, i.e., selling off all my property, getting to my eyeballs in > debt, etc) if I'd be really motivated (i.e., to find a pervert who raped > my daughter and posted video of that on Freenet, or something). Even if > nodes would be paying $50 to join (which I don't think is a realistic > amount), an attacker would still need to come up with just $5M, which > isn't that much for a middle-sized private company, and is chump change > for any government agency. > > 2a. Yes, that means that, in my opinion, we can't look to money for > scarcity, it should be obtained from somewhere else. To find it, I think > that threat model should be defined better.
I agree. Another way to think of "scarcity" is by defining the "bottleneck" required for a sybil attack. If we can engineer it such that a legitimate user only needs to "find and mash his yubikey once a month", that is near-trivial, but if a sybil network needs someone to mash 100k yubikeys per month... you start to get a bottleneck, no? What other options are then available but to higher dedicated yubikey mashers (now I wonder if that can be done by an auto-loader-type machine), or try and compromise yubico corporate? Beyond more expensive & far-out ideas, that's the best I can come up with ATM. -- Robert Hailey
