Key Exchange - CompTIA Security+ SY0-701 - 1.4
How to Securely Share Encryption Keys?
The Challenge of Key Sharing
- Discusses the importance of having an encryption key known only by the encryptor and decryptor, highlighting a logistical challenge in sharing this key securely over the internet.
- Raises the question of how to share an encryption key without transferring it through insecure mediums like the internet.
Out-of-Band Key Exchange
- Introduces the concept of out-of-band key exchange, where keys are transferred using methods outside of network communication, such as physical delivery or phone calls.
- Emphasizes that due to time constraints on the internet, in-band key exchange is often necessary for immediate encryption needs.
In-Band Key Exchange Mechanisms
- Explains that in-band key exchange can utilize additional encryption mechanisms, such as asymmetric encryption to secure symmetric keys during transmission.
- Describes how session keys can be used temporarily; a client encrypts a random symmetric key with a server's public key and sends it for decryption with the server's private key.
Creating Symmetric Keys Using Public Key Cryptography
- Discusses another method for creating symmetric keys between two devices using public-key cryptography without sending the symmetric key itself across the network.