CREST Practitioner Security Analyst (CPSA) Practice

What is a key characteristic of asymmetric encryption?

1. It uses the same key for both encryption and decryption

2. It requires a pair of keys

3. It is faster than symmetric encryption

4. It cannot be used for secure data transmission

The correct answer is: It requires a pair of keys

A key characteristic of asymmetric encryption is that it requires a pair of keys. In asymmetric encryption, two distinct keys are utilized: a public key, which can be shared openly, and a private key, which remains confidential. This dual-key approach allows for secure communications, where anyone can encrypt a message using the public key, but only the owner of the corresponding private key can decrypt it. This system enhances security and enables functionalities like digital signatures, which verify the integrity and origin of a message. The other choices do not correctly represent asymmetric encryption. Using the same key for both encryption and decryption describes symmetric encryption, which does not utilize a key pair. While asymmetric encryption is generally slower than symmetric encryption due to its complex mathematical operations, it provides unique advantages, mainly concerning key distribution and security. Lastly, contrary to the statement that it cannot be used for secure data transmission, asymmetric encryption is widely used in secure communications, such as in SSL/TLS protocols, allowing secure data transmission over the internet.