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Alice's Birthday Party (Part 1) Level 2

by Lehrstuhl für Kryptologie u. IT-Sicherheit, Ruhr-Universität Bochum, published on 10/14/2010

Alice sends encrypted invitations for her birthday party to her friends. As it turns out, two of her friends use the same RSA parameter N. This fact allows an adversary Eve to decrypt the encrypted message without knowing the corresponding secret key. Where does Alice's party take place? The codeword for this challenge is the location of Alice's party.