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Since WEP and WPA/WPA2 encrypt the payload of 802.11 MAC frames and we know that MAC goes under the Data Link Layer (Layer 2), can we also assume that encryption occurs in Layer 2 as well?

At least with protocols such as HTTPS I know for sure that encryption occurs in Layer 6.

Thanks in advance.

croussou
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2 Answers2

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802.11 Protocol The IEEE 802 standards committee defines two separate layers, the Logical Link Control (LLC) and media access control, for the Data-Link layer of the OSI model. The IEEE 802.11 wireless standard defines the specifications for the physical layer and the media access control (MAC) layer that communicates up to the LLC layer, as shown in the following figure.

source

^-summary: IEEE 802.11 is over 2 layers

from: Wireless LAN Medium Access Control (MAC) and Physical Layer (PHY) specifications 802.11 reference model

actual implementations of WEP, TKIP, and CCMP services are transparent to the LLC and other layers above the mac sublayer.

encryption occurs on layer 2

exeral
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Hard to say, I am not an expert to this, but I think it's somewhere like Layer 1 and 1/4

Eg. WPA2 is defined in IEEE 802.11 extension with letter i. Because Layer 1 usualy defines physical properties of signals and encoding(+encryption), I suppose it definately belongs here.

On the other side, there is some more communication which looks like L2. Every wireless client has it's own MAC-like address (BSSID) and they are exchanging keys for encryption so there are some elements pointing to Layer 2, but it's much closer to Layer 1.

ISO/OSI Model is just theoretical and many practicaly used protocols cannot be divided strinctly into one layer, so my opinion is Layer 1.25

EDIT: It definately cannot be higher than L2, because we can do eg. ARP request over wlan which is connecting L2 and L3.

Dragonn
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  • Interesting and mostly accurate approach to thinking of the problem. The other answer has the correct technical details. – Chris S Apr 09 '14 at 15:44
  • Nice explanation, it somehow compliments what was written above. Thanks guys. – croussou Apr 11 '14 at 07:25