The Randomized Fuzzy Equality Sample Clauses

The Randomized Fuzzy Equality. Functionality Figure 4 shows the ran-‌ RFE fPAKE and F domized fuzzy equality functionality FP , which is essentially what FP would look RFE like assuming authenticated channels. The primary difference between FP P fPAKE RFE is that the only pass-string guesses allowed by FP are the ones actually used as pro- tocol inputs; this limits the adversary to guessing by corrupting one of the participating The functionality FRFE is parameterized by a security parameter λ and a tolerance δ. It interacts with an adversary S and two parties P0 and P1 via the following queries: – Upon receiving a query (NewSession, sid, pwi) from party Pi ∈ {P0, P1}: • If this is the first NewSession query, or if this is the second NewSession query and there • Send (NewSession, sid, Pi) to S; – Upon receiving a query (TestPwd, sid, Pi) from the adversary S, Pi ∈ {P0, P1}: is a record (P1−i, pw1−i), then record (Pi, pwi). If records of the form (P0, pw0) and (P1, pw1) do not exist, if P1−i is not corrupted, or this is to the adversary S. – query not the first TestPwd query for Pi, ignore this query. Otherwise, if d(pw0, pw1) ≤ δ, send pwi Upon receiving a If there are no records of the form (Pi, pwi) and (P1−i, pw1−i), or if this is not the first NewKey (NewKey, sid, Pi, sk) from the adversary S P , ∈ {P , P }: i

The Randomized Fuzzy Equality. Functionality Figure 3 shows‌ RFE the randomized fuzzy equality functionality FP , which is essentially what F P fPAKE would look like assuming authenticated channels. The primary differ- RFE and F ence between FP P fPAKE is that the only pass-string guesses allowed by F P RFE are the ones actually used as protocol inputs; this limits the adversary to guessing by corrupting one of the participating parties, not through man in the fPAKE middle attacks. Like FP , if a pass-string guess is “similar enough”, the entire pass-string is leaked. This leakage could be replaced with any other leakage from RFE