802.1AE is the IEEE MAC Security standard (also known as MACsec) which defines connectionless data confidentiality and integrity for media access independent protocols. It is standardized by the IEEE 802.1 working group.
Key management and the establishment of secure associations is outside the scope of 802.1AE, but is specified by 802.1X-2010.
The 802.1AE standard specifies the implementation of a MAC Security Entities (SecY) that can be thought of as part of the stations attached to the same LAN, providing secure MAC service to the client. The standard defines
- MACsec frame format, which is similar to the Ethernet frame, but includes additional fields:
- Secure Connectivity Associations that represent groups of stations connected via unidirectional Secure Channels
- Security Associations within each secure channel. Each association uses its own key (SAK). More than one association is permitted within the channel for the purpose of key change without traffic interruption (standard requires devices to support at least two)
- A default cipher suite of GCM-AES-128 (Galois/Counter Mode of Advanced Encryption Standard cipher with 128-bit key)
- GCM-AES-256 using a 256 bit key was added to the standard 5 years later.
Security tag inside each frame in addition to EtherType includes:
- association number within the channel
- packet number to provide unique initialization vector for encryption and authentication algorithms as well as protection against replay attack
- optional LAN-wide secure channel identifier (not required on point-to-point links).
The IEEE 802.1AE (MACsec) standard specifies a set of protocols to meet the security requirements for protecting data traversing Ethernet LANs.
MACsec allows unauthorised LAN connections to be identified and excluded from communication within the network. In common with IPsec and SSL, MACsec defines a security infrastructure to provide data confidentiality, data integrity and data origin authentication.
By assuring that a frame comes from the station that claimed to send it, MACSec can mitigate attacks on Layer 2 protocols.
- 2006 – Original publication (802.1AE-2006)
- 2011 – 802.1AEbn amendment adds the option to use 256 bit keys to the standard. (802.1AEbn-2011)
- 2013 – 802.1AEbw amendment defines GCM-AES-XPN-128 and GCM-AES-XPN-256 cipher suites in order to extend the packet number to 64 bits. (802.1AEbw-2013)
- 2017 – 802.1AEcg amendment specifies Ethernet Data Encryption devices. (802.1AEcg-2017)