Institute of Information Science - University of Miskolc

1. Alice generates a pair of keys: e (public key) and d (private key). In this context e means (encryption key) and d (decryption key).

2. She keeps d secret, but makes e public.

3. If Bob wants to send a message to Alice, he uses Alice's public key e.

4. Based on the equation \( c = E(e, m) \), only Alice can decrypt \( c \) using her private key, with \( m = D(d, c) \), where \( m \) is the message.

5. If anyone else wants to send a message to Alice, they can also use her public key e.

The system is secure from a decryption perspective because only Alice can decrypt the message, but Alice can never be sure if Bob sent the message, as the public key e can be used by anyone.