Cisco Wireless Security

WPA – Wireless Protected Access

WPA, includes TKIP

WPA2, includes AES

WPA3, removes older standards like TKIP

Authentication, abstracted

Courtesy of BRKEWN-3004.

sequenceDiagram
    participant S as Supplicant<br/>Phone, PC, Laptop, Etc.
    participant A as Authenticator<br/>(WLC)
    participant AS as Authentication Server<br/>(ISE)

    A->>S: Association Response
    A->>S: Identity Request
    S->>A: Identity Response
    A->>AS: Identity Response
    S<<->>AS: EAP Type Negotiation
    S<<->>AS: Authentication Sequence
    AS->>A: EAP Success
    A->>S: EAP Success

Encryption, abstracted

Courtesy of BRKEWN-3004.

PTK — Pairwise Transient Key

GTK — Group Transient Key

PMK — Pairwise Master Key

STA — Station

Anonce – Authenticator nonce, a random value generated by the authenticator

Snonce — Supplicant nonce, a random value generated by the supplicant

\(PTK = SHA(PMK + ANonce + SNonce + AP MAC + STA MAC)\)

sequenceDiagram
    participant S as Supplicant
    participant A as Authenticator<br/>(WLC)
    participant AS as Authentication Server<br/>(ISE)

    Note over AS: PMK
    AS->>A: EAP Success (PMK)
    A->>S: EAP Success
    Note over S: PMK

    rect rgb(235, 245, 235)
    Note over S,A: Four-Way Handshake
    A->>S: ANonce
    S->>A: SNonce, MIC
    Note over S,A: PTK, GTK derived
    A->>S: ANonce, MIC, GTK, Sequence #
    S->>A: ACK
    end

References

IEEE 802.11x Part 11: Wireless LAN Medium Access Control (MAC) and Physical Layer (PHY) Specifications

Cisco Live - Understanding Wireless Security - Mark Krischer - BRKEWN-3004