Data encryption before transmission and decryption after reception occurs at which OSI layer?

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Accepted Answer

Presentation Layer - The Presentation Layer is the sixth layer in the OSI model. It is mainly responsible for how data is shown or presented to the application layer. One of its key jobs is handling encryption and decryption.

Before data is sent over the network, it is encrypted at the Presentation Layer to keep it secure. When the data reaches the other end, it is decrypted at the same layer so it can be read and understood.

Other tasks of the Presentation Layer include:

Data Encryption: Converts readable data into a secure form before transmission.
Data Decryption: Converts secure (encrypted) data back into readable form after reception.
Translation: Changes data formats between sender and receiver (e.g., EBCDIC to ASCII).
Compression: Reduces the size of data to improve transmission speed and efficiency.


This layer acts like a translator between systems. It ensures the data is secure and properly formatted before reaching the application. It is essential for services like emails, banking, and secure websites.

Conclusion: The correct answer is the Presentation Layer, as it handles encryption, decryption, translation, and compression to make communication safe and understandable.

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