A Level Computer Science OCR Test 2025 – 400 Free Practice Questions to Pass the Exam

Asymmetric encryption is characterized by the use of different keys for the encryption and decryption processes, which is the fundamental aspect that distinguishes it from symmetric encryption. In asymmetric encryption, a pair of keys is utilized: a public key, which is used to encrypt data, and a private key, which is used to decrypt it. This approach enhances security, as the public key can be freely distributed while the private key remains confidential with the owner.

In contrast to this, symmetric encryption relies on a single shared key for both the encryption and decryption processes, meaning that the same key must be used securely between both parties.

The other concepts reflected in the options highlight variations from the principles of asymmetric encryption: using the same key underscores the nature of symmetric encryption, the idea of not using keys at all misrepresents both encryption methods, and the exclusive association with data compression does not indicate the function of asymmetric encryption in secure communication. Therefore, the aspect of involving different keys is the correct distinguishing feature for asymmetric encryption.