How do Alice and Bob use public-key encryption?

Two parties (Alice and Bob) might use public-key encryption as follows: First, Alice generates a public/private key pair. If Bob wants to send Alice an encrypted message, he asks her for her public key. Alice sends Bob her public key over a nonsecure network, and Bob uses this key to encrypt a message.

How does Bob decrypt a message?

Alice sends Bob her public key over a nonsecure network, and Bob uses this key to encrypt a message. Bob sends the encrypted message to Alice, and she decrypts it by using her private key. If Bob received Alice's key over a nonsecure channel, such as a public network, Bob is open to a man-in-the-middle attack.

What is a public key cryptosystem?

In public key cryptosystems there are two keys, a public one used for encryption and and private one for decryption. 1 Alice and Bob agree on a public key cryptosystem. 2 Bob sends Alice his public key, or Alice gets it from a public database. 3 Alice encrypts her plaintext using Bob’s public key and sends it to Bob.

What does Alice and Bob mean in cryptography?

Overview[edit] An example of an "Alice and Bob" used in cryptography Alice and Bob are the names of fictional characters used for convenience and to aid comprehension. For example, "How can Bob send a private message M to Alice in a public-key cryptosystem?"