osi presentation layer and encryption

[sarahr202]

Hi every body

how is everyone doing ?

I was reading about the role of presentation layer. One of the role is encryption.  My question  we have been relying on lower layers  to provide encryption( e.g 802.11n)

Why is the encrption  not implemented by presentation layer?

Thanks and have a great day.

[abhischa · Accepted solution]

Hi,

Actually, encryption (and  decryption) is performed at the presentation layer also. This ensures the  security of the data as it travels down the protocol stack. For example, the Secure Sockets Layer (SSL) protocol.  However, not all encryption is done at layer 6, some encryption is often  done at lower layers in the protocol stack.

Encryption is present in the Layer-2 Layer-3 (IPSEC) and Layer-4 (TSL). The distinct advantages of Layer-2 encryption are lower overhead on data  packets, reduced maintenance costs. Apart from these, there is no reduction in quality of service. Thus, i guess L-2 encryption is preferred. But, this also depends on the network and the kind of encryption you require, for eg: layer 2 is hop by hop and layer 3 (IPSEC) is end to end.

Hope that helps!

Cheers,

Abhishek.

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