In this case, you are asked to attack an RSA encrypted message. Imagine being the attacker:...

 

Transcribed Image Text:

In this case, you are asked to attack an RSA encrypted message. Imagine being the attacker: You obtain the ciphertext C=1141 by eavesdropping on a certain connection. The public key is Kpub=(n,e)=(2623,2111). a. Consider the encryption formula, C=M mod n. All variables except the plaintext M are known. Why can't you simply solve the equation for M? b. In order to determine the private key d, you have to calculate d=e mod (n). There is an efficient expression for calculating (n). Can we use this formula here? c. Calculate the plaintext M by computing the private key d through factoring n=p.q. Does this approach remain suitable for number with a length of 1024 bit or more? In this case, you are asked to attack an RSA encrypted message. Imagine being the attacker: You obtain the ciphertext C=1141 by eavesdropping on a certain connection. The public key is Kpub=(n,e)=(2623,2111). a. Consider the encryption formula, C=M mod n. All variables except the plaintext M are known. Why can't you simply solve the equation for M? b. In order to determine the private key d, you have to calculate d=e mod (n). There is an efficient expression for calculating (n). Can we use this formula here? c. Calculate the plaintext M by computing the private key d through factoring n=p.q. Does this approach remain suitable for number with a length of 1024 bit or more?