Archive for the 'Mathematics' Category



RSA cryptography question?

Sunday 17 October 2010 @ 7:22 am
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geoff asked:

Alice wants to send a message to Bob securely, using
the RSA cryptosystem. Explain how this works (you do
not have to justify related theorems), by considering an
example where the public key is (n, e) = (77, 5). More
specically, and the private key, and explain the decryption/encryption process for each message 1 <= P <= 77.
Is there a restriction on the message P that Alice can
send? (P, 77) = 1.




Challenging Question?

Friday 31 July 2009 @ 10:02 pm
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sheriefhalawa asked:

Me and my friend have reserved rooms in hotels. I want to handle him golden statue. Both me and him have 1 suit case, 1 lock and 1 key each (each one’s key is for his own lock). We are not allowed to leave our rooms but we are allowed to send each other things via the room handlers, which are not trust-worthy. If they see a golden statue, they steal it. If they see a key, they make themselves identical copies of it. Is there someway using some sequence of transactions that I can transfer the statue securely to my friend? (A golden statue for the best answer :)