Okay, so you want to hash the numbers as the are collected in the field, salted with a memorised (manually entered) salt, and store only the hashes. So that should the laptop fall into the wrong hands, the real numbers are irretrievable.

But then have a set of rainbow tables back at your secure location, built using the memorised salt+hash, that allows you to reverse the hashes.

Barring that the bad guys torture you/the collectors for the memorised salt and build their own rainbow tables, that seems quite secure. (To me, but I'm no expert!).

Examine what is said, not who speaks -- Silence betokens consent -- Love the truth but pardon error.
"Science is about questioning the status quo. Questioning authority".
In the absence of evidence, opinion is indistinguishable from prejudice.
"I'd rather go naked than blow up my ass"

In reply to Re^7: Creating a rainbow table for a ten-digit number: Advice? by BrowserUk
in thread Creating a rainbow table for a ten-digit number: Advice? by willyyam

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