What is the main difference between symmetric and asymmetric encryption?

The main difference between symmetric and asymmetric encryption lies in the key usage for the encryption and decryption processes. In symmetric encryption, the same key is utilized for both tasks—encrypting the plaintext and decrypting the ciphertext. This characteristic ensures that both the sender and receiver must have access to the secret key, requiring secure key management practices to prevent unauthorized access.

In contrast, asymmetric encryption employs a pair of keys—a public key and a private key. The public key can be shared openly and is used to encrypt the data, while the private key, known only to the owner, is employed for decryption. As a result, asymmetric encryption supports functionalities like digital signatures and secure key exchange, enhancing security in scenarios where secure key distribution is challenging.

Understanding the distinct nature of key usage is critical for selecting the appropriate encryption method based on the specific requirements of security, speed, and key management in various applications.