Comment on How Facebook Knows When Its Ads Influence Your Offline PurchasesparentComments−moab11yWhy on earth would you have to brute force all numbers? You can do this optimally: just hash the numbers you see (or get requests for).−dmurray11ySo that I can cold call someone who might be interested in my product, even though DataLogix only told me the hash of their phone number.−moab11yYou've already hashed all numbers on your end, so it's trivial to figure this out (hash the hash?). Hopefully I'm not thinking about this wrong, but it does seem feasible.
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Why on earth would you have to brute force all numbers? You can do this optimally: just hash the numbers you see (or get requests for).
So that I can cold call someone who might be interested in my product, even though DataLogix only told me the hash of their phone number.
You've already hashed all numbers on your end, so it's trivial to figure this out (hash the hash?). Hopefully I'm not thinking about this wrong, but it does seem feasible.