All RSA cryptosystem has public key N = 35 and e = 7. Messages are encrypted one letter at a time, converting letters to numbers by A = 2, B = 3, .... Z = 27, space = 28. Showing your working, encrypt the message: BE GOOD.
Find the decryption exponent d and decrypt the message: 20 23 26 7 15 16
This choice of N and e has several weaknesses - name at least two different ones. Even if a good choice of N and e is made, the method of encrypting one letter at a time has weaknesses.
Describe how we might find the plaintext if a very long cyphertext is given.
Eve intercepts the RSA message 365, 0, 4845, 14930, 2608, 2608, 0 sent from Alice to Bob. Alice and Bob are not using the scheme above.
How does it seem they are converting letters to numbers? Decrypt the message.