Microsoft Certified Solutions Developer (MCSD) Certification Practice Test

Which of the following statements about asymmetric encryption is true?

1. It uses one key for both encryption and decryption

2. It allows for high-speed data encryption

3. It requires the exchange of a private key

4. It uses a public and a private key

The correct answer is: It uses a public and a private key

Asymmetric encryption is a cryptographic technique that employs two distinct keys: a public key and a private key. The public key is used for encrypting data, while the private key is used for decrypting it. This dual-key architecture is a fundamental characteristic of asymmetric encryption, making it particularly advantageous for secure communications over untrusted networks, such as the internet. When someone wants to send a secure message, they can use the recipient's public key to encrypt the message, ensuring that only the recipient, who possesses the corresponding private key, can decrypt and read it. This method enhances security because the public key can be shared openly without compromising the integrity of the communications. The other statements do not accurately describe asymmetric encryption. For example, using one key for both encryption and decryption pertains to symmetric encryption, where a single key is utilized. High-speed data encryption is generally more characteristic of symmetric encryption due to its simpler algorithm, while the exchange of a private key suggests a misunderstanding of the principles behind public-key cryptography, as the private key should always remain confidential and not be shared.