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seen Dec 13 '11 at 1:54

Jul
28
awarded  Nice Question
Dec
11
comment Random oracle model proofs and programmability
Wow, this was great! Thank you so much!
Dec
7
comment Random oracle model proofs and programmability
I think I put the question in a wrong way. I was reading the random oracle model chapter in the Katz-Lindell book and it says that in the random oracle, all queries that any of the parties make to the oracle are public, and then it writes that: "The reduction sees all the queries that A makes to the random oracle. This does not contradict the fact that queries are private. While that is true in the formal model itself, here we are using A as a subroutine within a reduction." I just don't quite understand how it is different and how this is "allowed".
Dec
7
comment Random oracle model proofs and programmability
I see what you mean about the hash functions, thank you! I now realize I worded my question wrong, I did mean to say methodology.
Dec
7
comment Random oracle model proofs and programmability
I have one last question: All the queries to the random oracle are private, but "the reduction" can see all the queries that are made to the oracle. Does this mean that when proving with reduction, we introduce a new adversary who can see all the queries but no one else can? Doesn't this contradict the random oracle's definition if it is defined in a way that all the queries are private?
Dec
7
comment Random oracle model proofs and programmability
This is great! Thanks a lot!
Dec
7
comment Random oracle model proofs and programmability
Yes, I understand that. But let's assume that you want to prove the security of scheme A, you prove this security in the ROM. And then you implement this scheme A and instead of using the random oracle (because it doesn't exist), you implement it with using a hash function B. So why don't you prove that scheme A is secure when you use function B as opposed to proving that scheme A is secure with a random oracle?
Dec
7
awarded  Student
Dec
7
asked Random oracle model proofs and programmability