Encryption is typically done at which OSI layer, and decryption is also handled there?

Encryption is typically done at which OSI layer, and decryption is also handled there?

• A. Application layer
• B. Transport layer
• C. Presentation layer
• D. Network layer

Answer: (C)

Encryption and decryption are handled at the Presentation layer because this layer is responsible for transforming data into a format suitable for transmission, including applying and removing encryption, as well as compression and translation to a common representation. When the application passes data up, the Presentation layer encrypts it before it’s sent down through the Transport and Network layers. On the receiving end, the process is reversed: the Presentation layer decrypts the incoming ciphertext and then passes the plaintext to the application. While applications can implement encryption themselves, the OSI model assigns the encryption/decryption function to the Presentation layer, making it the best answer.

Encryption and decryption are handled at the Presentation layer because this layer is responsible for transforming data into a format suitable for transmission, including applying and removing encryption, as well as compression and translation to a common representation. When the application passes data up, the Presentation layer encrypts it before it’s sent down through the Transport and Network layers. On the receiving end, the process is reversed: the Presentation layer decrypts the incoming ciphertext and then passes the plaintext to the application. While applications can implement encryption themselves, the OSI model assigns the encryption/decryption function to the Presentation layer, making it the best answer.