Which of the following is a common use case for asymmetric encryption?

Asymmetric encryption, also known as public key cryptography, is primarily used to secure communication and establish trusted connections. One of its key use cases is in secure email communication, where a sender can encrypt a message using the recipient's public key, ensuring that only the recipient can decrypt it with their private key. This process safeguards the content of emails from unauthorized access.

Additionally, asymmetric encryption is essential for establishing secure web connections through HTTPS. When a client connects to a server, asymmetric encryption is used during the initial handshake to exchange encryption keys securely. This allows subsequent data transferred between the client and server to be encrypted and secure from eavesdropping.

Other options listed do not align with the core principles or applications of asymmetric encryption. For instance, storing passwords in plaintext is a security risk and not associated with encryption practices. Creating digital copies of physical documents involves digital scanning instead of encryption, and performing network traffic analysis typically uses different methodologies that may not involve direct encryption mechanisms.