it is time for me to be a real security nerd and finally obtain pgp key
but first: figuring out what the heck that means
Conversation
some questions to hunt down:
how the Heck does asymmetrical encryption work
what are pgp signatures good for and how do they work
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single key encryption makes sense to me - you take a number and a message, perform math, obtain encrypted message, then perform math but backwards with the same number to get decrypted message
but, given a public key, shouldnt it be possible to calculate the private key?
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like, presumably you stick a number into a function, and it spits out a public/private pair of numbers
and there should (?) be some way of getting one from the other
hmm
i guess not all functions have inverses, which might make that tricky
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e.g. the way RSA works is that the public key is a semiprime n (the product of two primes p, q which are secret) and a number e, and the private key is d = e^{-1} mod n; this is calculable from the public key but not *efficiently* (as far as anyone knows)
conjecturally you can't compute d without computing the factorization n = pq, and also conjecturally factorization is hard; further conjecturally, computing d like this is the only way to break RSA
(that's 3 independent conjectures!)
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whoops, sorry, that should've been d = e^{-1} mod lambda(n) where lambda(n) is the carmichael function, whatevs
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