Let [A-Z] denote the set of all capital letters from A to Z. The password w is a string in [A-Z]*.
For w = w_1...w_n ∈ [A-Z]^n, let ascii(w) := ascii(w_1) || ... || ascii(w_n) where ascii(w_i) is the decimal ASCII code of w_i for every i. For example, ascii(ABC) = 656667, since ascii(A) = 65, ascii(B) = 66, ascii(C) = 67.
Further let N := 264356242932330620591879762011459333409.
The password w has been encrypted to
c = 259252555055790712660181286804144327401 = ascii(w)^151089236568313654499150506467499 mod N.
Recover w from c by finding a suitable exponent d s.t. c^d mod N = ascii(w). Tip: Every prime factor p of N satisfies (60000 < p < 70000).