Key Exchange

Question 1

What is a logistical challenge in key exchange?

Answer 1

Sharing an encryption key across an insecure medium without physically transferring the key.

Question 2

What is out-of-band key exchange?

Answer 2

A method of sharing a symmetric key without sending it over the internet, using methods like telephone, courier, or in-person communication.

Question 3

What is in-band key exchange?

Answer 3

A method of sharing a symmetric key over the network, often protected with additional encryption or using asymmetric encryption to deliver the key.

Question 4

Why is real-time encryption/decryption important?

Answer 4

There is a need for fast security without compromising the integrity of the security measures.

Question 5

How does a client share a symmetric session key with a server?

Answer 5

The client encrypts a random symmetric key with the server’s public key, allowing the server to decrypt it and use it for data encryption.

Question 6

What is a session key?

Answer 6

A temporary symmetric key used to encrypt data during a session, which is shared using asymmetric encryption.

Question 7

Why should session keys be implemented carefully?

Answer 7

They need to be changed often (ephemeral keys) and should be unpredictable to maintain security.

Question 8

How is a symmetric key created from asymmetric keys?

Answer 8

By using public and private key cryptography, where mathematical operations are used to derive a symmetric key from asymmetric key pairs.

Question 9

What is the primary advantage of using asymmetric encryption in key exchange?

Answer 9

It allows secure transmission of a symmetric key over an insecure channel, ensuring confidentiality during the exchange.

Question 10

What are ephemeral keys?

Answer 10

Temporary keys used for a short duration to enhance security by minimizing the risk of key compromise.