CREST Practitioner Security Analyst (CPSA) Practice

Which of the following is an example of symmetric encryption?

1. RSA

2. RC4

3. Diffie-Hellman

4. ECDSA

The correct answer is: RC4

Symmetric encryption uses a single key for both the encryption and decryption processes, which means that both parties need access to the same key to securely communicate. RC4 is a stream cipher and is a well-known example of symmetric encryption; it employs a secret key to encrypt data streams. In contrast, RSA is an asymmetric encryption algorithm, which utilizes a public and a private key for secure communications, making it distinct from symmetric methods. Diffie-Hellman is primarily used for secure key exchange rather than encryption, and ECDSA, which stands for Elliptic Curve Digital Signature Algorithm, is also an asymmetric algorithm used for digital signatures. Therefore, RC4's role as a symmetric cipher makes it the correct choice in this context.