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1. I have a ciphertext message produced by RSA encryption with key (e,n)=(5,2881) and i'm trying to find the plain text message of

0504 1874 0347 0515 2088 2356 0736 0468

I found the euler-phi function to be 42*66=2772 and found the modular inverse to be 1109 but i'm having trouble finding C^1109(mod2881) for each block of four. can anyone help with this?

2. I'm trying to show that if the encryption exponent 3 is used for the RSA cryptosystem by 3 different people with different moduli, and a plaintext message P encrypted usin each of their keys can be recovered from the resulting 3 ciphertext messages.

I've set it up to the congruences c_i congruent to P^3(mod n_i), i = 1,2,3 but i'm not really sure where to go from here. can anyone help?

thanks