Question

just need help with part c

key and public key cryptography methods 2. (a) Explain the difference between the symmetric (b) In the famou s RSA algorithm for public key cryptography, very large prime numbers are used so as to make ult for the attackers to find from their product the prime factors. However, for an illustration of the ideas behind the RSA algorithm, you could chooses two small prime numbers 7 and 11, and a public key e 13 to encrypt the data and uses d-37 to decrypt the data. Indicate why (c, 77) and (d, 77) are valid public and private keys. (2 Points) (4 Points) (c) Show how the number 5 is encrypted and decrypted using the above keys.

Answer 1

The answers for your question given below. If any doubts let me know.

(e, n ) (13,7 7) C5mod 77 13 (5*. 5 53 mod 77 x 5 mod 77 a 304 x 304x5) mod 77 a304 modt 77 304 mod 77 X 5 mod 77

ciphertext of plaintext 5 is 26

dacryehon MこCa mod n Hee C 5 37 (513X 54s") mod 71 53 med 771 53 mod 77 X53 mod 77 x5mod 77 ) mod 77 sr ) 二47

plaintext of ciphertext 5 is 47