## What key does Alice use to encrypt to Bob?

public key

Alice encrypts with her public key, and the only key to decrypt this should be her private key, but with transform encryption, Bob can decrypt with his private key.

**Why are Alice and Bob used in cryptography?**

Alice and Bob are fictional characters commonly used as placeholders in discussions about cryptographic systems and protocols, and in other science and engineering literature where there are several participants in a thought experiment.

**How can the secret key be securely shared between Alice and Bob?**

Each communicating pair of people need to share a key. Alice obtains his public key, encrypts a message using this key and then sends it to Bob. Bob is then able to decrypt the message using the secret part of his own key.

### When Patricia receives a message from Gary?

When Patricia receives a message from Gary, she wants to be able to demonstrate to Sue that the message actually came from Gary. What goal of cryptography is Patricia attempting to achieve? Gary is sending a message to Patricia. He wants to ensure that nobody tampers with the message while it is in transit.

**Who came up with Alice and Bob?**

In 1978, professors Ron Rivest, Adi Shamir and Len Adleman (RSA) chose the names Alice and Bob to make it easier for people to understand how public key encryption works.

**Why can’t Bob choose 1 as the public key e?**

1 is a bad choice because it makes very easy to reverse-engineer a key that will open Bob’s padlock, which is the opposite of what we want. This is a Python fragment which generates a RSA key with e = 1 .

#### What happens if you use a wrong secret key?

If the wrong secret key is used to decrypt then the output should be unreadable with high probability. This is the crux of public key cryptography, because now anyone can encrypt a message and send it to you using your public key, but only you can decrypt it with your secret key.

**How do Bob and Alice use their public and private keys?**

They have kept their private keys securely to themselves and have sent their public keys directly to each other. Bob uses Alice’s public key to encrypt the message and sends it to her. Alice uses her private key to decrypt the message.

**Can Bob decrypt Alice’s secret message?**

So, if Alice and Bob are using public key infrastructure instead of the symmetric encryption method, Alice could encrypt the secret message using Bob’s public key that she has. Bob, with his private key, is then the only person who can decrypt the message.

## Can Alice send a digital certificate to Bob?

So, for example, Bob can send his digital certificate to Alice, which is a convenient way for Alice to validate that Bob is who he claims to be (through Victor’s “fingerprint”), and also contains Bob’s Public key, that Alice can then use to encrypt and send some information to Bob.

**Who are Alice and Bob?**

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?” is believed to be easier to describe and understand than “How can B send a private message M to A in a public-key cryptosystem?”