Question 5

Asymmetric encryption should be used.

Asymmetric encryption is the recommended type of encryption for scenarios where secure key exchange is necessary. This method utilizes a pair of keys, a public key for encryption and a private key for decryption, enhancing security in communication.

A) VPN

VPN, or Virtual Private Network, is not a type of encryption but rather a technology that creates a secure connection over the internet. While it can use encryption protocols, it is not inherently an encryption method itself and thus does not fit the requirement of the question.

B) IPSec

IPSec is a protocol suite for securing internet protocol communications through encryption and authentication. While it is effective for securing data in transit, it is not classified as a type of encryption like asymmetric encryption, making it less suitable for the specific context of the question.

C) Asymmetric

Asymmetric encryption is specifically designed for secure key exchanges and is the most appropriate option for scenarios requiring secure communication. It allows users to encrypt messages without the need to share a secret key, thus providing a strong security model.

D) Hashing

Hashing is a process used to convert data into a fixed-size string of characters, which is typically used for data integrity checks rather than encryption. It does not provide confidentiality since it is a one-way function, making it unsuitable for the purpose of encryption outlined in the question.

Conclusion

Asymmetric encryption is the definitive choice due to its ability to facilitate secure data exchange without the need for a shared secret. In contrast, VPN, IPSec, and hashing either do not represent encryption methods or serve different purposes, thus failing to meet the specific requirements of the question.