Question

Which encryption method is used when the sender and receiver use an instance of the same key for encryption and decryption purposes?

A). Symmetric algorithm
B). Asymmetric algorithm
C). Block cipher
D). Diffusion

Answer 1

The encryption method where the same key is used for both encryption and decryption is a symmetric algorithm, which is efficient and widely used.

Step-by-step explanation:

The encryption method used when the sender and receiver use an instance of the same key for both encryption and decryption purposes is known as a symmetric algorithm. In a symmetric encryption system, the same key is used for both securing (encrypting) the data and for allowing the authorized recipient to access (decrypt) the data. It is essential that this key remains a secret between the sender and receiver to ensure the confidentiality of the communication.

Symmetric algorithms are generally faster and more efficient than their counterparts, asymmetric algorithms, which use different keys for encryption and decryption. Examples of symmetric algorithms include AES (Advanced Encryption Standard) and DES (Data Encryption Standard).

Answer 2

The encryption method is used when the sender and receiver use an instance of the same key for encryption and decryption purposes

A). Symmetric algorithm

Step-by-step explanation:

Symmetric algorithms use a single key for both encryption and decryption making option A Symmetric algorithm the correct choice. In symmetric encryption the same secret key is applied for both the sender's encryption and the receiver's decryption ensuring confidentiality and security of the communication.

Symmetric encryption is computationally efficient as it involves less complex mathematical operations compared to asymmetric algorithms. The key used in symmetric encryption is shared between the communicating parties and the security relies on keeping this key confidential. The encryption and decryption processes are reciprocal and the efficiency of symmetric algorithms makes them suitable for various applications including secure data transmission and storage.

In contrast asymmetric algorithms involve pairs of public and private keys with one key used for encryption and the other for decryption. While asymmetric encryption provides additional security features like digital signatures it is generally slower than symmetric encryption. Therefore when the sender and receiver use the same key for encryption and decryption it is indicative of a symmetric algorithm providing an efficient and secure method for data protection in various communication scenarios.