Salahuddin559

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seen Oct 14 '12 at 11:54

Oct
14
awarded  Student
Oct
12
awarded  Scholar
Oct
12
accepted RSA keys finding when messages are known
Oct
11
comment RSA keys finding when messages are known
Yes, it is actually more like "signing" only. I got the answer for my question, but, why should not sign with private key encryption? (I understand now that it is not an encryption, but something like signing only, this was the purpose of it before as well, to sign it with sender id). Is there any theoretical reason for it? For secrecy or problem of attacks? If we use, for example, 128 bit keys, is attacks for private key a problem? NOTE: I will mark it as answered, as soon as this is cleared. Problem is already there are many crypto systems in the app, signing will be another one.
Oct
11
comment RSA keys finding when messages are known
I also got your digital signature idea, that also makes sense. If this RSA encryption becomes heavy (for first layer), I will use it, yes.
Oct
11
comment RSA keys finding when messages are known
"You seem to be asking whether it can be broken under a chosen plaintext attack," did not get you. I am saying, if number of possible messages is n (<= 10, lets say), then can the attacker (gained with this knowledge, and the 10 possible messages), guess the keys?
Oct
11
comment RSA keys finding when messages are known
We do two encryptions, one with senders private key, but on top it, for the same message, we encrypt again with receivers public key. So, for any attacker has to first decrypt using receivers private key, which is not possible. However, the senders private key is used (in the first layer) only to ensure that the "sender cant deny 'it is him who sent the message' " later.
Oct
11
asked RSA keys finding when messages are known